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Sample records for continuous breeding evolving

  1. Continuous Evaluation of Evolving Behavioral Intervention Technologies

    PubMed Central

    Mohr, David C.; Cheung, Ken; Schueller, Stephen M.; Brown, C. Hendricks; Duan, Naihua

    2013-01-01

    Behavioral intervention technologies (BITs) are web-based and mobile interventions intended to support patients and consumers in changing behaviors related to health, mental health, and well-being. BITs are provided to patients and consumers in clinical care settings and commercial marketplaces, frequently with little or no evaluation. Current evaluation methods, including RCTs and implementation studies, can require years to validate an intervention. This timeline is fundamentally incompatible with the BIT environment, where technology advancement and changes in consumer expectations occur quickly, necessitating rapidly evolving interventions. However, BITs can routinely and iteratively collect data in a planned and strategic manner and generate evidence through systematic prospective analyses, thereby creating a system that can “learn.” A methodologic framework, Continuous Evaluation of Evolving Behavioral Intervention Technologies (CEEBIT), is proposed that can support the evaluation of multiple BITs or evolving versions, eliminating those that demonstrate poorer outcomes, while allowing new BITs to be entered at any time. CEEBIT could be used to ensure the effectiveness of BITs provided through deployment platforms in clinical care organizations or BIT marketplaces. The features of CEEBIT are described, including criteria for the determination of inferiority, determination of BIT inclusion, methods of assigning consumers to BITs, definition of outcomes, and evaluation of the usefulness of the system. CEEBIT offers the potential to collapse initial evaluation and postmarketing surveillance, providing ongoing assurance of safety and efficacy to patients and consumers, payers, and policymakers. PMID:24050429

  2. Continuous evaluation of evolving behavioral intervention technologies.

    PubMed

    Mohr, David C; Cheung, Ken; Schueller, Stephen M; Hendricks Brown, C; Duan, Naihua

    2013-10-01

    Behavioral intervention technologies (BITs) are web-based and mobile interventions intended to support patients and consumers in changing behaviors related to health, mental health, and well-being. BITs are provided to patients and consumers in clinical care settings and commercial marketplaces, frequently with little or no evaluation. Current evaluation methods, including RCTs and implementation studies, can require years to validate an intervention. This timeline is fundamentally incompatible with the BIT environment, where technology advancement and changes in consumer expectations occur quickly, necessitating rapidly evolving interventions. However, BITs can routinely and iteratively collect data in a planned and strategic manner and generate evidence through systematic prospective analyses, thereby creating a system that can "learn." A methodologic framework, Continuous Evaluation of Evolving Behavioral Intervention Technologies (CEEBIT), is proposed that can support the evaluation of multiple BITs or evolving versions, eliminating those that demonstrate poorer outcomes, while allowing new BITs to be entered at any time. CEEBIT could be used to ensure the effectiveness of BITs provided through deployment platforms in clinical care organizations or BIT marketplaces. The features of CEEBIT are described, including criteria for the determination of inferiority, determination of BIT inclusion, methods of assigning consumers to BITs, definition of outcomes, and evaluation of the usefulness of the system. CEEBIT offers the potential to collapse initial evaluation and postmarketing surveillance, providing ongoing assurance of safety and efficacy to patients and consumers, payers, and policymakers.

  3. The continually evolving Clostridium difficile species.

    PubMed

    Cairns, Michelle D; Stabler, Richard A; Shetty, Nandini; Wren, Brendan W

    2012-08-01

    Clostridium difficile is a spore-forming Gram-positive bacterium that causes chronic diarrhea and sometimes life-threatening disease mainly in elderly and hospitalized patients. The reported incidence of C. difficile infection has changed dramatically over the last decade and has been related to the emergence of distinct clonal lineages that appear more transmissible and cause more severe infection. These include PCR ribotypes 027, 017 and more recently 078. Population biology studies using multilocus sequence typing and whole-genome comparisons has helped to define the C. difficile species into four clonal complexes that include PCR ribotypes 027, 017, 078 and 023, as well as a general grouping of most other PCR ribotypes. Further analysis of strains from diverse sources and geographical origins reveal significant microdiversity of clonal complexes and confirms that C. difficile is continuing to evolve. The study of C. difficile represents a real-time global evolutionary experiment where the pathogen is responding to a range of selective pressures created by human activity and practices in healthcare settings. The advent of whole-genome sequencing coupled with phylogeny (phylogeography and phylohistory) will provide unprecedented detail on the local and global emergence and disappearance of C. difficile clones, and facilitate more rational approaches to disease control. This review will highlight the emergence of virulent C. difficile clones and our current understanding of molecular epidemiology of the species.

  4. The Continuously Evolving Land Use Control Climate in FUSRAP - 12285

    SciTech Connect

    Ewy, Ann; Waples, Richard

    2012-07-01

    coordination as well as coordination and input from stakeholders. With guidance on LUCs available from a number of entities, the USACE now has the opportunity to develop consistency in determining how LUCs are handled on FUSRAP projects. The FUSRAP ER, ER 200-1-4, is currently being revised and will broadly touch on LUCs. This broad approach was a result of recognizing the magnitude of variances and site specific components that come into play when applying LUCs to our FUSRAP sites. As land use controls scenarios continue to arise on our FUSRAP sites, the methods for how our project teams address those will continue to evolve. The Program is continuing to develop guidance on how to address LUCs. In the interim, our FUSRAP projects can share lessons learned on the LUCs they are implementing. (authors)

  5. Boom and bust in continuous time evolving economic model

    NASA Astrophysics Data System (ADS)

    Mitchell, L.; Ackland, G. J.

    2009-08-01

    We show that a simple model of a spatially resolved evolving economic system, which has a steady state under simultaneous updating, shows stable oscillations in price when updated asynchronously. The oscillations arise from a gradual decline of the mean price due to competition among sellers competing for the same resource. This lowers profitability and hence population but is followed by a sharp rise as speculative sellers invade the large un-inhabited areas. This cycle then begins again.

  6. Tree-breeding technique: some effects of continuous bagging

    Treesearch

    Jonathan W. Wright

    1951-01-01

    In tree-breeding operations, it is standard practice to protect the tree flowers with vegetable parchment or sausage-casing bags during the pollination period so no unwanted pollen can get to them. Since the bags often damage the tree, they are usually removed as soon as the pollination period ends - within 2 or 3 weeks.

  7. Reproductive toxicity of ethylene glycol monoethyl ether tested by continuous breeding of CD-1 mice

    SciTech Connect

    Lamb, J.C. IV; Gulati, D.K.; Russell, V.S.; Hommel, L.; Sabharwal, P.S.

    1984-08-01

    The reproductive toxicity of ethylene glycol monoethyl ether (EGEE) was evaluated in the Fertility Assessment by Continuous Breeding protocol. Both male and female CD-1 mice were given 0, 0.5, 1.0 or 2% EGEE in the drinking water and were housed as breeding pairs continuously for 14 weeks. Significant adverse effects on fertility were seen at 1 and 2% but not at 0.5%. After the continuous breeding phase of this test was completed, treated males were housed with control females and treated females with control males and fertility and reproduction were compared to the corresponding pairs of control male and control female mice. Both males and females from the 1 and 2% groups were affected. Testicular atrophy decreased sperm motility and increased abnormal sperm were noted in the treated males, but no specific anomalies were detected in the females. 7 references, 1 figure, 7 tables.

  8. Genetic Characterization of Continually Evolving Highly Pathogenic H5N6 Influenza Viruses in China, 2012–2016

    PubMed Central

    Li, Meng; Zhao, Na; Luo, Jing; Li, Yuan; Chen, Lin; Ma, Jiajun; Zhao, Lin; Yuan, Guohui; Wang, Chengmin; Wang, Yutian; Liu, Yanhua; He, Hongxuan

    2017-01-01

    H5N6 is a highly pathogenic avian influenza (HPAI) and a zoonotic disease that causes recurring endemics in East Asia. At least 155 H5N6 outbreaks, including 15 human infections, have been reported in China. These repeated outbreaks have increased concern that the H5N6 virus may cross over to humans and cause a pandemic. In February, 2016, peafowls in a breeding farm exhibited a highly contagious disease. Post-mortem examinations, including RT-PCR, and virus isolation, confirmed that the highly pathogenic H5N6 influenza virus was the causative agent, and the strain was named A/Pavo Cristatus/Jiangxi/JA1/2016. In animal experiments, it exhibited high pathogenicity in chickens and an estimated median lethal dose in mice of ~104.3 TCID50. A phylogenetic analysis showed that JA1/2016 was clustered in H5 clade 2.3.4.4. FG594-like H5N6 virus from Guangdong Province was the probable predecessor of JA1/2016, and the estimated divergence time was June 2014. Furthermore, we found that H5N6 influenza viruses can be classified into the two following groups: Group 1 and Group 2. Group 2 influenza viruses have not been detected since the end of 2014, whereas Group 1 influenza viruses have continually evolved and reassorted with the “gene pool” circulating in south China, resulting in the rise of novel subtypes of this influenza virus. An increase in the number of its identified hosts, the expanding range of its distribution, and the continual evolution of H5N6 AIVs enhance the risk that an H5N6 virus may spread to other continents and cause a pandemic. PMID:28293218

  9. ANALYSIS OF GENOMIC DNA METHYLATION AND GENE EXPRESSION IN CHINESE CABBAGE (Brassica rapa L. ssp. pekinensis) AFTER CONTINUOUS SEEDLING BREEDING.

    PubMed

    Tao, L; Wang, X L; Guo, M H; Zhang, Y W

    2015-08-01

    Vernalization plays a key role in the bolting and flowering of Chinese cabbage (Brassica rapa L. ssp. pekinensis). Plants can switch from vegetative to reproductive growth and then bolt and flower under low temperature induction. The economic benefits of Chinese cabbage will decline significantly when the bolting happens before the vegetative body fully grows due to a lack of the edible value. It was found that continuous seedling breeding reduced the heading of Chinese cabbage and led to bolt and flower more easily. In the present study, two inbred lines, termed A161 and A105, were used as experiment materials. These two lines were subjected to vernalization and formed four types: seeds-seedling breeding once, seedling breeding twice, seedling breeding thrice and normal type. Differences in plant phenotype were compared. DNA methylation analysis was performed based on MSAP method. The differential fragments were cloned and analyzed by qPCR. Results showed that plants after seedling breeding thrice had a loosen heading leaves, elongated center axis and were easier to bolt and flower. It is suggested that continuous seedling breeding had a weaker winterness. It was observed that genome methylation level decreased with increasing generation. Four differential genes were identified, short for BraAPC1, BraEMP3, BraUBC26, and BraAL5. Fluorescent qPCR analysis showed that expression of four genes varied at different reproduction modes and different vernalization time. It is indicated that these genes might be involve in the development and regulation of bolting and flowering of plants. Herein, the molecular mechanism that continuous seedling breeding caused weaker winterness was analyzed preliminarily. It plays an important guiding significance for Chinese cabbage breeding.

  10. Bred to breed?! Implications of continuous mating on the emotional status of mouse offspring.

    PubMed

    Lerch, Sandra; Brandwein, Christiane; Dormann, Christof; Gass, Peter; Chourbaji, Sabine

    2015-02-15

    Working with mice represents a smart method to study pathophysiological mechanisms in vivo. However, using animals as model organisms also bears immense caveats. While many aspects in animal research are meanwhile standardized (e.g. nutrition, housing, health) the breeding environment remains unaddressed. Moreover, since the "production" of mice is mostly performed pragmatically, continuous mating (CM) represents a common method to boost the amount of offspring. This condition implies simultaneous pregnancy and lactation in presence of the male, which is associated with increased costs for the breeding dam. Facing the widely-accepted impact of perinatal conditions, our aim was to elucidate how CM affects emotional behaviour of mouse offspring. We therefore compared pregnant mice in CM with mice raising their pups without potentially disturbing influences. According to our hypothesis CM-deriving offspring should demonstrate increased anxiety and depression-like behaviour shaped by pre- and postnatal stress of the mother. Maternal care, i.e. nest building and pup retrieval, was analysed around delivery. To assess the emotional state of the offspring, males and females of either condition were exposed to a behavioural test battery for exploration, anxiety and fear, social and despair behaviour. In addition we analysed corticosterone as stressphysiological correlate. Our study demonstrates that CM affects the emotional phenotype regarding nearly all parameters addressed. These findings emphasize (i) the impact of the perinatal environment on stress-associated behaviour such as depression, and (ii) the need to imply perinatal conditions in the experimental design to decrease the risk of artefacts and increase the overall validity of animal studies.

  11. Peripheral oxygen transport and utilization in rats following continued selective breeding for endurance running capacity.

    PubMed

    Howlett, Richard A; Kirkton, Scott D; Gonzalez, Norberto C; Wagner, Harrieth E; Britton, Steven L; Koch, Lauren G; Wagner, Peter D

    2009-06-01

    Untrained rats selectively bred for either high (HCR) or low (LCR) treadmill running capacity previously demonstrated divergent physiological traits as early as the seventh generation (G7). We asked whether continued selective breeding to generation 15 (G15) would further increase the divergence in skeletal muscle capillarity, morphometry, and oxidative capacity seen previously at G7. At G15, mean body weight was significantly lower (P < 0.001) in the HCR rats (n = 11; 194 +/- 3 g) than in LCR (n = 12; 259 +/- 9 g) while relative medial gastrocnemius muscle mass was not different (0.23 +/- 0.01 vs. 0.22 +/- 0.01% total body weight). Normoxic (Fi(O(2)) = 0.21) Vo(2max) was 50% greater (P < 0.001) in HCR despite the lower absolute muscle mass, and skeletal muscle O(2) conductance (measured in hypoxia; Fi(O(2)) = 0.10) was 49% higher in HCR (P < 0.001). Muscle oxidative enzyme activities were significantly higher in HCR (citrate synthase: 16.4 +/- 0.4 vs. 14.0 +/- 0.6; beta-hydroxyacyl-CoA dehydrogenase: 5.2 +/- 0.2 vs. 4.2 +/- 0.2 mmol.kg(-1).min(-1)). HCR rats had approximately 36% more total muscle fibers and also 36% more capillaries in the medial gastrocnemius. Because average muscle fiber area was 35% smaller, capillary density was 36% higher in HCR, but capillary-to-fiber ratio was the same. Compared with G7, G15 HCR animals showed 38% greater total fiber number with an additional 25% decrease in mean fiber area. These data suggest that many of the skeletal muscle structural and functional adaptations enabling greater O(2) utilization in HCR at G7 continue to progress following additional selective breeding for endurance capacity. However, the largest changes at G15 relate to O(2) delivery to skeletal muscle and not to the capacity of skeletal muscle to use O(2).

  12. Whole-genome sequencing of six dog breeds from continuous altitudes reveals adaptation to high-altitude hypoxia

    PubMed Central

    Gou, Xiao; Wang, Zhen; Li, Ning; Qiu, Feng; Xu, Ze; Yan, Dawei; Yang, Shuli; Jia, Jia; Kong, Xiaoyan; Wei, Zehui; Lu, Shaoxiong; Lian, Linsheng; Wu, Changxin; Wang, Xueyan; Li, Guozhi; Ma, Teng; Jiang, Qiang; Zhao, Xue; Yang, Jiaqiang; Liu, Baohong; Wei, Dongkai; Li, Hong; Yang, Jianfa; Yan, Yulin; Zhao, Guiying; Dong, Xinxing; Li, Mingli; Deng, Weidong; Leng, Jing; Wei, Chaochun; Wang, Chuan; Mao, Huaming; Zhang, Hao; Ding, Guohui; Li, Yixue

    2014-01-01

    The hypoxic environment imposes severe selective pressure on species living at high altitude. To understand the genetic bases of adaptation to high altitude in dogs, we performed whole-genome sequencing of 60 dogs including five breeds living at continuous altitudes along the Tibetan Plateau from 800 to 5100 m as well as one European breed. More than 150× sequencing coverage for each breed provides us with a comprehensive assessment of the genetic polymorphisms of the dogs, including Tibetan Mastiffs. Comparison of the breeds from different altitudes reveals strong signals of population differentiation at the locus of hypoxia-related genes including endothelial Per-Arnt-Sim (PAS) domain protein 1 (EPAS1) and beta hemoglobin cluster. Notably, four novel nonsynonymous mutations specific to high-altitude dogs are identified at EPAS1, one of which occurred at a quite conserved site in the PAS domain. The association testing between EPAS1 genotypes and blood-related phenotypes on additional high-altitude dogs reveals that the homozygous mutation is associated with decreased blood flow resistance, which may help to improve hemorheologic fitness. Interestingly, EPAS1 was also identified as a selective target in Tibetan highlanders, though no amino acid changes were found. Thus, our results not only indicate parallel evolution of humans and dogs in adaptation to high-altitude hypoxia, but also provide a new opportunity to study the role of EPAS1 in the adaptive processes. PMID:24721644

  13. Evolution of Comprehensive Care, Part 3. Periodontal Treatment Continues to Evolve.

    PubMed

    Kurtzman, Gregori M; Hughes, Mary K

    2015-05-01

    Perio treatment has evolved beyond simple scaling with hand instruments. Ultrasonics and diode lasers have improved both the efficiency of treatment as well as treatment prognosis to arresting the disease process and gaining clinical attachment and decreasing pocket depth. Add to this the benefits of adjunct medicaments both at time of treatment via site placement and during routine home care by the patient, and we are able to tip treatment outcome in a more favorable direction. Periodontology has been closely linked to systemic health both as a causative agent to health issues and as a secondary site for some medical conditions. Dentistry has truly--and finally--become a part of total healthcare.

  14. When the sun never sets: diverse activity rhythms under continuous daylight in free-living arctic-breeding birds

    PubMed Central

    Steiger, Silke S.; Valcu, Mihai; Spoelstra, Kamiel; Helm, Barbara; Wikelski, Martin; Kempenaers, Bart

    2013-01-01

    Circadian clocks are centrally involved in the regulation of daily behavioural and physiological processes. These clocks are synchronized to the 24 h day by external cues (Zeitgeber), the most important of which is the light–dark cycle. In polar environments, however, the strength of the Zeitgeber is greatly reduced around the summer and winter solstices (continuous daylight or continuous darkness). How animals time their behaviour under such conditions has rarely been studied in the wild. Using a radio-telemetry-based system, we investigated daily activity rhythms under continuous daylight in Barrow, Alaska, throughout the breeding season in four bird species that differ in mating system and parental behaviour. We found substantial diversity in daily activity rhythms depending on species, sex and breeding stage. Individuals exhibited either robust, entrained 24 h activity cycles, were continuously active (arrhythmic) or showed ‘free-running’ activity cycles. In semipalmated sandpipers, a shorebird with biparental incubation, we show that the free-running rhythm is synchronized between pair mates. The diversity of diel time-keeping under continuous daylight emphasizes the plasticity of the circadian system, and the importance of the social and life-history context. Our results support the idea that circadian behaviour can be adaptively modified to enable species-specific time-keeping under polar conditions. PMID:23782884

  15. When the sun never sets: diverse activity rhythms under continuous daylight in free-living arctic-breeding birds.

    PubMed

    Steiger, Silke S; Valcu, Mihai; Spoelstra, Kamiel; Helm, Barbara; Wikelski, Martin; Kempenaers, Bart

    2013-08-07

    Circadian clocks are centrally involved in the regulation of daily behavioural and physiological processes. These clocks are synchronized to the 24 h day by external cues (Zeitgeber), the most important of which is the light-dark cycle. In polar environments, however, the strength of the Zeitgeber is greatly reduced around the summer and winter solstices (continuous daylight or continuous darkness). How animals time their behaviour under such conditions has rarely been studied in the wild. Using a radio-telemetry-based system, we investigated daily activity rhythms under continuous daylight in Barrow, Alaska, throughout the breeding season in four bird species that differ in mating system and parental behaviour. We found substantial diversity in daily activity rhythms depending on species, sex and breeding stage. Individuals exhibited either robust, entrained 24 h activity cycles, were continuously active (arrhythmic) or showed 'free-running' activity cycles. In semipalmated sandpipers, a shorebird with biparental incubation, we show that the free-running rhythm is synchronized between pair mates. The diversity of diel time-keeping under continuous daylight emphasizes the plasticity of the circadian system, and the importance of the social and life-history context. Our results support the idea that circadian behaviour can be adaptively modified to enable species-specific time-keeping under polar conditions.

  16. Evolving curriculum design: a novel framework for continuous, timely, and relevant curriculum adaptation in faculty development.

    PubMed

    Lieff, Susan Janet

    2009-01-01

    The time lag between needs assessment and implementation of faculty development curricula assumes a certain stability of participants' individual and contextual needs which may not reflect the often complex and shifting priorities in health professional schools. In addition to the variability of issues they face, participants are typically better able to recognize and articulate their needs once engaged in a curriculum.This article is a conceptual description of how applying an umbrella strategy to curriculum design illuminated an iterative methodology for continuous adaptation of the 2004-2006 University of Toronto Education Scholars Program in real time to the emergent needs of participants and their context. The general goals or umbrella for the core curriculum were determined by a broad-based environmental scan. In keeping with a learner-centered collaborative program, a number of process strategies were developed to solicit input from participants during the two years of the program. These included creating a dialogue space, use of class and program evaluations, modified Delphi needs assessments, and opinion leader interviews. Adaptation of curriculum was enabled by protection of curriculum time and flexibility of course leadership. The application of strategy theory to curriculum design has not been previously described. This iterative approach enabled course leadership to successfully identify multiple unperceived issues to address. With this unique and cyclical process, curricular relevance and timeliness are ensured as well as enhancing participant motivation and engagement, consistent with adult learning principles. This methodology should be considered by course directors of all continuing professional development programs.

  17. Ontogenetic variations and structural adjustments in mammals evolving prolonged to continuous dental growth.

    PubMed

    Gomes Rodrigues, Helder; Lefebvre, Rémi; Fernández-Monescillo, Marcos; Mamani Quispe, Bernardino; Billet, Guillaume

    2017-07-01

    Studying dental ontogeny in mammals can provide valuable insight on the evolution of their masticatory apparatus and their related adaptations. The multiple acquisitions of a prolonged to continuous growth of teeth in herbivorous mammals in response to high abrasion represent an intensively investigated issue. However, the ontogenetic and architectural patterns associated with these repeated dental innovations remain poorly known. Here, we focused on two case studies corresponding to distant mammalian clades, the extinct Mesotheriidae (Notoungulata), which shared some striking dental features with the extant Ctenodactylidae (Rodentia). We studied the impact of prolonged to continuous growth of molars on their occlusal complexity, their relative size and their dynamics in the jaw. We found that variations of occlusal complexity patterns are the result of paedomorphic or peramorphic heterochronic processes impacting dental crown. We showed that variations in both upper and lower molar proportions generally follow the inhibitory developmental cascade model. In that context, prolonged dental growth implies transitory adjustments due to wear, and also involves dental migration and loss when combined with molar lengthening. Interestingly, these features may be present in many mammals having prolonged dental growth, and emphasize the crucial need of considering these aspects in future evolutionary and developmental studies.

  18. Ontogenetic variations and structural adjustments in mammals evolving prolonged to continuous dental growth

    NASA Astrophysics Data System (ADS)

    Gomes Rodrigues, Helder; Lefebvre, Rémi; Fernández-Monescillo, Marcos; Mamani Quispe, Bernardino; Billet, Guillaume

    2017-07-01

    Studying dental ontogeny in mammals can provide valuable insight on the evolution of their masticatory apparatus and their related adaptations. The multiple acquisitions of a prolonged to continuous growth of teeth in herbivorous mammals in response to high abrasion represent an intensively investigated issue. However, the ontogenetic and architectural patterns associated with these repeated dental innovations remain poorly known. Here, we focused on two case studies corresponding to distant mammalian clades, the extinct Mesotheriidae (Notoungulata), which shared some striking dental features with the extant Ctenodactylidae (Rodentia). We studied the impact of prolonged to continuous growth of molars on their occlusal complexity, their relative size and their dynamics in the jaw. We found that variations of occlusal complexity patterns are the result of paedomorphic or peramorphic heterochronic processes impacting dental crown. We showed that variations in both upper and lower molar proportions generally follow the inhibitory developmental cascade model. In that context, prolonged dental growth implies transitory adjustments due to wear, and also involves dental migration and loss when combined with molar lengthening. Interestingly, these features may be present in many mammals having prolonged dental growth, and emphasize the crucial need of considering these aspects in future evolutionary and developmental studies.

  19. Evolved aniline catabolism in Acinetobacter calcoaceticus during continuous culture of river water.

    PubMed Central

    Wyndham, R C

    1986-01-01

    Adaptation of Acinetobacter calcoaceticus from river water to aniline depends on the dynamics of parent and mutant populations. The parent, Acinetobacter strain DON26 phenotype Ani0, was common in river water and assimilated aniline effectively at micromolar concentrations, but was inhibited at higher concentrations of aniline. The Ani0 phenotype was also characterized by a broad specificity for oxidation of chloroanilines by aniline-induced cells. The mutant Ani+ phenotype was represented by DON2, isolated from a population of less than 100 cells ml-1 in a mixed river water culture, and by DON261, isolated during continuous culture of DON26. Ani+ strains assimilated aniline at a greater maximum specific rate than the parent and were able to grow at concentrations of aniline greater than 16 mM. These strains cooxidized phenol after growth at high aniline concentrations, but showed reduced activity toward chloroanilines. These changes plus kinetic data, oxygen uptake data, and the results of auxanography indicate that the mutant has an increased activity and altered specificity of the initial enzyme in the aniline catabolic pathway. The parent strain, DON26, was at a selective advantage relative to the mutant at low concentrations of aniline, but was replaced by the mutant when aniline concentrations increased. Adaptation of the mixed river water community to aniline involved selection of both phenotypes. Reversion of the Ani+ to Ani0 phenotype occurred at a frequency of 10(-2) in the absence of aniline selection. Plasmid content was not altered during either acquisition or loss of the Ani+ phenotype. Adaptive changes in Acinetobacter spp. populations illustrate important differences in the catabolic activities of natural and pollutant selected strains.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:3707123

  20. Transformation of fruit trees. Useful breeding tool or continued future prospect?

    PubMed

    Petri, César; Burgos, Lorenzo

    2005-02-01

    Regeneration and transformation systems using mature plant material of woody fruit species have to be achieved as a necessary requirement for the introduction of useful genes into specific cultivars and the rapid evaluation of resulting horticultural traits. Although the commercial production of transgenic annual crops is a reality, commercial genetically-engineered fruit trees are still far from common. In most woody fruit species, transformation and regeneration of commercial cultivars are not routine, generally being limited to a few genotypes or to seedlings. The future of genetic transformation as a tool for the breeding of fruit trees requires the development of genotype-independent procedures, based on the transformation of meristematic cells with high regeneration potential and/or the use of regeneration-promoting genes. The public concern with the introduction of antibiotic resistance into food and the restrictions due to new European laws that do not allow deliberate release of plants transformed with antibiotic-resistance genes highlight the development of methods that avoid the use of antibiotic-dependent selection or allow elimination of marker genesfrom the transformed plant as a research priority in coming years.

  1. Assessment of ethylene glycol monobutyl and monophenyl ether reproductive toxicity using a continuous breeding protocol in Swiss CD-1 mice.

    PubMed

    Heindel, J J; Gulati, D K; Russell, V S; Reel, J R; Lawton, A D; Lamb, J C

    1990-11-01

    A continuous breeding reproduction study design was utilized to examine the reproductive toxicity of ethylene glycol monobutyl ether (EGBE) and ethylene glycol monophenyl ether (EGPE). Swiss CD-1 mice were administered EGBE in drinking water (0, 0.5, 1.0, and 2.0%, i.e., 0.7, 1.3, and 2.1 g/kg body wt/day) and EGPE was administered via the feed (0, 0.25, 1.25, and 2.5%, i.e., 0, 0.4, 2.0, and 4 g/kg body wt/day). Both male and female mice were dosed for 7 days prior to and during a 98-day cohabitation period. EGBE was toxic at the high (2%) and mid dose (1%) to adult F0 female mice: 13 out of 22 females at the high dose and 6 out of 20 at the mid dose died during the cohabitation period. Both the high- and mid-dose animals produced fewer litters/pair, fewer pups/litter, with decreased pup weight. These effects occurred in the presence of decreased body weight, decreased water consumption, and increased kidney weight. A crossover mating trial indicated that the reproductive effects could be attributed primarily to an effect on the female. This was substantiated at necropsy where testes and epididymis weights were normal as were sperm number and motility. Fertility of the offspring of the 0.5% group was normal in the presence of increased liver weights. With respect to EGPE, there was no change in the ability to produce five litters during the continuous breeding period. There was, however, a significant but small (10-15%) decrease in the number of pups/litter and in pup weight in the high-dose group. A crossover mating trial suggested a female component of the reproductive toxicity of EGPE. While fertility was only minimally compromised, severe neonatal toxicity was observed. By Day 21 there were only 8 out of 40 litters in the mid- and high-dose groups which had at least one male and female/litter. Second generation reproductive performance of the mid-dose group (1.25%) was unaffected except for a small decrease in live pup weight. In summary the reproductive

  2. Continuous movement behavior of humpback whales during the breeding season in the southwest Indian Ocean: on the road again!

    PubMed

    Dulau, Violaine; Pinet, Patrick; Geyer, Ygor; Fayan, Jacques; Mongin, Philippe; Cottarel, Guillaume; Zerbini, Alexandre; Cerchio, Salvatore

    2017-01-01

    Humpback whales are known to undertake long-distance migration between feeding and breeding sites, but their movement behavior within their breeding range is still poorly known. Satellite telemetry was used to investigate movement of humpback whales during the breeding season and provide further understanding of the breeding ecology and sub-population connectivity within the southwest Indian Ocean (SWIO). Implantable Argos satellite tags were deployed on 15 whales (7 males and 6 females) during the peak of the breeding season in Reunion Island. A switching-state-space model was applied to the telemetry data, in order to discriminate between "transiting" and "localized" movements, the latter of which relates to meandering behavior within putative breeding habitats, and a kernel density analysis was used to assess the spatial scale of the main putative breeding sites. Whales were tracked for up to 71 days from 31/07/2013 to 16/10/2013. The mean transmission duration was 25.7 days and the mean distance travelled was 2125.8 km. The tracks showed consistent movement of whales from Reunion to Madagascar, demonstrating a high level of connectivity between the two sub-regions, and the use of yet unknown breeding sites such as underwater seamounts (La Perouse) and banks (Mascarene Plateau). A localized movement pattern occurred in distinct bouts along the tracks, suggesting that whales were involved in breeding activity for 4.3 consecutive days on average, after which they resume transiting for an average of 6.6 days. Males visited several breeding sites within the SWIO, suggesting for the first time a movement strategy at a basin scale to maximize mating. Unexpectedly, females with calf also showed extensive transiting movement, while they engaged in localized behavior mainly off Reunion and Sainte-Marie (East Madagascar). The results indicated that whales from Reunion do not represent a discrete population. Discrete breeding sites were identified, thereby highlighting

  3. Toward an Evolved Concept of Landrace

    PubMed Central

    Casañas, Francesc; Simó, Joan; Casals, Joan; Prohens, Jaime

    2017-01-01

    The term “landrace” has generally been defined as a cultivated, genetically heterogeneous variety that has evolved in a certain ecogeographical area and is therefore adapted to the edaphic and climatic conditions and to its traditional management and uses. Despite being considered by many to be inalterable, landraces have been and are in a constant state of evolution as a result of natural and artificial selection. Many landraces have disappeared from cultivation but are preserved in gene banks. Using modern selection and breeding technology tools to shape these preserved landraces together with the ones that are still cultivated is a further step in their evolution in order to preserve their agricultural significance. Adapting historical landraces to present agricultural conditions using cutting-edge breeding technology represents a challenging opportunity to use them in a modern sustainable agriculture, as an immediate return on the investment is highly unlikely. Consequently, we propose a more inclusive definition of landraces, namely that they consist of cultivated varieties that have evolved and may continue evolving, using conventional or modern breeding techniques, in traditional or new agricultural environments within a defined ecogeographical area and under the influence of the local human culture. This includes adaptation of landraces to new management systems and the unconscious or conscious selection made by farmers or breeders using available technology. In this respect, a mixed selection system might be established in which farmers and other social agents develop evolved landraces from the variability generated by public entities. PMID:28228769

  4. Toward an Evolved Concept of Landrace.

    PubMed

    Casañas, Francesc; Simó, Joan; Casals, Joan; Prohens, Jaime

    2017-01-01

    The term "landrace" has generally been defined as a cultivated, genetically heterogeneous variety that has evolved in a certain ecogeographical area and is therefore adapted to the edaphic and climatic conditions and to its traditional management and uses. Despite being considered by many to be inalterable, landraces have been and are in a constant state of evolution as a result of natural and artificial selection. Many landraces have disappeared from cultivation but are preserved in gene banks. Using modern selection and breeding technology tools to shape these preserved landraces together with the ones that are still cultivated is a further step in their evolution in order to preserve their agricultural significance. Adapting historical landraces to present agricultural conditions using cutting-edge breeding technology represents a challenging opportunity to use them in a modern sustainable agriculture, as an immediate return on the investment is highly unlikely. Consequently, we propose a more inclusive definition of landraces, namely that they consist of cultivated varieties that have evolved and may continue evolving, using conventional or modern breeding techniques, in traditional or new agricultural environments within a defined ecogeographical area and under the influence of the local human culture. This includes adaptation of landraces to new management systems and the unconscious or conscious selection made by farmers or breeders using available technology. In this respect, a mixed selection system might be established in which farmers and other social agents develop evolved landraces from the variability generated by public entities.

  5. The influence of eastern North American autumnal migrant monarch butterflies (Danaus plexippus L.) on continuously breeding resident monarch populations in southern Florida.

    PubMed

    Knight, Amy; Brower, Lincoln P

    2009-07-01

    In Florida, the eastern North American population of the monarch butterfly exhibits geographic variability in population structure and dynamics. This includes the occurrence of migrants throughout the peninsula during the autumnal migration, occasional overwintering clusters that form along the Gulf Coast, remigrants from Mexico that breed in north-central Florida during the spring, and what have been assumed to be year-round, resident breeding populations in southern Florida. The work reported here focused on two monarch populations west of Miami and addressed four questions: Are there permanent resident populations of monarchs in southern Florida? Do these breed continuously throughout the year? Do they receive northern monarchs moving south during the autumn migration? Do they receive overwintered monarchs returning via Cuba or the Yucatan during the spring remigration from the Mexican overwintering area? Monthly collections and counts of spermatophores in the bursa copulatrices of females established that a resident population of continuously breeding monarchs exists year-round in southern Florida. It was determined through cardenolide fingerprinting that most of the butterflies had bred on the local southern Florida milkweed species, Asclepias curassavica. During the autumn migration period, however, some monarchs had fed on the northern milkweed, Asclepias syriaca. It appears that instead of migrating to Mexico, these individuals travel south through peninsular Florida, break diapause, mate with and become incorporated into the resident breeding populations. None of the monarchs captured in spring had the A. syriaca cardenolide fingerprint, which is evidence against the southern Florida populations receiving overwintered remigrants from Cuba, Central America or Mexico.

  6. Breeding lettuce for improved fresh-cut processing

    USDA-ARS?s Scientific Manuscript database

    Lettuce is a widely grown vegetable that is used to make fresh-cut salads, which are popular with consumers due to their convenience. Production and processing of fresh-cut lettuce is continually evolving, offering more products and becoming more efficient. Breeding new lettuce cultivars specialized...

  7. Cardiac imaging of congenital heart diseases during interventional procedures continues to evolve: Pros and cons of the main techniques.

    PubMed

    Hascoët, Sebastien; Warin-Fresse, Karine; Baruteau, Alban-Elouen; Hadeed, Khaled; Karsenty, Clement; Petit, Jérôme; Guérin, Patrice; Fraisse, Alain; Acar, Philippe

    2016-02-01

    Cardiac catheterization has contributed to the progress made in the management of patients with congenital heart disease (CHD). First, it allowed clarification of the diagnostic assessment of CHD, by offering a better understanding of normal cardiac physiology and the pathophysiology and anatomy of complex malformations. Then, it became an alternative to surgery and a major component of the therapeutic approach for some CHD lesions. Nowadays, techniques have evolved and cardiac catheterization is widely used to percutaneously close intracardiac shunts, to relieve obstructive valvar or vessel lesions, and for transcatheter valve replacement. Accurate imaging is mandatory to guide these procedures. Cardiac imaging during catheterization of CHD must provide accurate images of lesions, surrounding cardiac structures, medical devices and tools used to deliver them. Cardiac imaging has to be 'real-time' with an excellent temporal resolution to ensure 'eyes-hands' synchronization and 'device-target area' accurate positioning. In this comprehensive review, we provide an overview of conventional cardiac imaging tools used in the catheterization laboratory in daily practice, as well as the effect of recent evolution and future imaging modalities.

  8. HIV-1 Continues To Replicate and Evolve in Patients with Natural Control of HIV Infection ▿ †

    PubMed Central

    Mens, Helene; Kearney, Mary; Wiegand, Ann; Shao, Wei; Schønning, Kristian; Gerstoft, Jan; Obel, Niels; Maldarelli, Frank; Mellors, John W.; Benfield, Thomas; Coffin, John M.

    2010-01-01

    Elucidating mechanisms leading to the natural control of HIV-1 infection is of great importance for vaccine design and for understanding viral pathogenesis. Rare HIV-1-infected individuals, termed HIV-1 controllers, have plasma HIV-1 RNA levels below the limit of detection by standard clinical assays (<50 to 75 copies/ml) without antiretroviral therapy. Although several recent studies have documented persistent low-grade viremia in HIV-1 controllers at a level not significantly different from that in HIV-1-infected individuals undergoing treatment with combination antiretroviral therapy (cART), it is unclear if plasma viruses are undergoing full cycles of replication in vivo or if the infection of new cells is completely blocked by host immune mechanisms. We studied a cohort of 21 HIV-1 controllers with a median level of viremia below 1 copy/ml, followed for a median of 11 years. Less than half of the cohort carried known protective HLA types (B*57/27). By isolating HIV-1 RNA from large volumes of plasma, we amplified single genome sequences of both pro-rt and env longitudinally. This study is the first to document that HIV-1 pro-rt and env evolve in this patient group, albeit at rates somewhat lower than in HIV-1 noncontrollers, in HLA B*57/27-positive, as well as HLA B*57/27-negative, individuals. Viral diversity and adaptive events associated with immune escape were found to be restricted in HIV-1 controllers, suggesting that replication occurs in the face of less overall immune selection. PMID:20926564

  9. Euthanasia—An Overview for Our Time A Report by the CMA Committee for Continuing Study of Evolving Trends in Society Affecting Life

    PubMed Central

    1973-01-01

    The Committee for the Continuing Study of Evolving Trends in Society Affecting Life was established by the CMA House of Delegates in 1971, following the consideration of a number of resolutions on the topic of abortion. The committee's charge was broadened, however, to include topics such as euthansia, biomedical engineering, medicine and religion, ecology and education. The committee's discussions, as its name indicates can cover a wide range of fields of interest to the medical profession. The following article is the first of several which the committee plans to publish, although the products of its deliberations may take the form of resolutions to future meetings of the House of Delegates. PMID:4694710

  10. Micromechanical analysis of a continuous fiber metal matrix composite including the effects of matrix viscoplasticity and evolving damage

    NASA Astrophysics Data System (ADS)

    Allen, D. H.; Jones, R. H.; Boyd, J. G.

    1994-03-01

    A THERMOMECHANICAL ANALYSIS of a metal matrix continuous fiber composite is performed herein. The analysis includes the effects of matrix inelasticity and interface cracking. Due to these nonlinearities, the analysis is performed computationally using the finite element method. Matrix inelasticity is modeled with a rate dependent viscoplasticity model. Interface fracture is modeled by the use of a nonlinear interface constitutive model. The problem formulation is summarized, and results are given for a typical SiC-Ti composite at elevated temperature. Preliminary results indicate that rate dependent viscoplasticity can be a significant mechanism for dissipating the energy available for interface fracture, thus contributing to improved macroscopic ductility of the composite.

  11. Apricot Breeding

    USDA-ARS?s Scientific Manuscript database

    Apricot orchard area and fruit production are increasing worldwide. Breeding programs engage in apricot development to provide new varieties to meet needs of producers and consumers. Over the last 20 years, breeders have used new techniques to assist in variety development and to increase breeding...

  12. Molecular breeding

    USDA-ARS?s Scientific Manuscript database

    Use of molecular and genomic tools to assist selection of parents or progeny has become an integral part of modern cotton breeding. In this chapter, the basic components of molecular cotton breeding are described. These components include: molecular marker development, genetic and physical map const...

  13. An Evolving Astrobiology Glossary

    NASA Astrophysics Data System (ADS)

    Meech, K. J.; Dolci, W. W.

    2009-12-01

    One of the resources that evolved from the Bioastronomy 2007 meeting was an online interdisciplinary glossary of terms that might not be universally familiar to researchers in all sub-disciplines feeding into astrobiology. In order to facilitate comprehension of the presentations during the meeting, a database driven web tool for online glossary definitions was developed and participants were invited to contribute prior to the meeting. The glossary was downloaded and included in the conference registration materials for use at the meeting. The glossary web tool is has now been delivered to the NASA Astrobiology Institute so that it can continue to grow as an evolving resource for the astrobiology community.

  14. 1980 breeding bird censuses

    SciTech Connect

    Raynor, G.S.

    1980-09-01

    As part of a program to characterize the plant and animal life of the Laboratory site and the surrounding region, the two breeding bird censuses originated in 1977 were continued in 1980. Coverage was below that of previous years due to illness and travel of some participants, but 11 trips were made to the BNL plot and 8 to the Westhampton plot. Each was censused by separate teams of three volunteer observers. The number of breeding species and number of territorial males on the BNL plot have progressively declined since 1977 but little change has taken place in either number of territories or species composition on the Westhampton plot.

  15. Simulated Breeding

    NASA Astrophysics Data System (ADS)

    Unemi, Tatsuo

    This chapter describes a basic framework of simulated breeding, a type of interactive evolutionary computing to breed artifacts, whose origin is Blind Watchmaker by Dawkins. These methods make it easy for humans to design a complex object adapted to his/her subjective criteria, just similarly to agricultural products we have been developing over thousands of years. Starting from randomly initialized genome, the solution candidates are improved through several generations with artificial selection. The graphical user interface helps the process of breeding with techniques of multifield user interface and partial breeding. The former improves the diversity of individuals that prevents being trapped at local optimum. The latter makes it possible for the user to fix features he/she already satisfied. These methods were examined through artistic applications by the author: SBART for graphics art and SBEAT for music. Combining with a direct genome editor and exportation to another graphical or musical tool on the computer, they can be powerful tools for artistic creation. These systems may contribute to the creation of a type of new culture.

  16. Blackberry breeding

    USDA-ARS?s Scientific Manuscript database

    Successful blackberry production and marketing depends on planting cultivars that are adapted to the region, efficiently produce high yields, and have the fruit quality the market, whether local or distant, demands. Blackberry breeding programs have developed cultivars that consumers like to eat and...

  17. Accelerating plant breeding.

    PubMed

    De La Fuente, Gerald N; Frei, Ursula K; Lübberstedt, Thomas

    2013-12-01

    The growing demand for food with limited arable land available necessitates that the yield of major food crops continues to increase over time. Advances in marker technology, predictive statistics, and breeding methodology have allowed for continued increases in crop performance through genetic improvement. However, one major bottleneck is the generation time of plants, which is biologically limited and has not been improved since the introduction of doubled haploid technology. In this opinion article, we propose to implement in vitro nurseries, which could substantially shorten generation time through rapid cycles of meiosis and mitosis. This could prove a useful tool for speeding up future breeding programs with the aim of sustainable food production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Culture evolves

    PubMed Central

    Whiten, Andrew; Hinde, Robert A.; Laland, Kevin N.; Stringer, Christopher B.

    2011-01-01

    Culture pervades human lives and has allowed our species to create niches all around the world and its oceans, in ways quite unlike any other primate. Indeed, our cultural nature appears so distinctive that it is often thought to separate humanity from the rest of nature and the Darwinian forces that shape it. A contrary view arises through the recent discoveries of a diverse range of disciplines, here brought together to illustrate the scope of a burgeoning field of cultural evolution and to facilitate cross-disciplinary fertilization. Each approach emphasizes important linkages between culture and evolutionary biology rather than quarantining one from the other. Recent studies reveal that processes important in cultural transmission are more widespread and significant across the animal kingdom than earlier recognized, with important implications for evolutionary theory. Recent archaeological discoveries have pushed back the origins of human culture to much more ancient times than traditionally thought. These developments suggest previously unidentified continuities between animal and human culture. A third new array of discoveries concerns the later diversification of human cultures, where the operations of Darwinian-like processes are identified, in part, through scientific methods borrowed from biology. Finally, surprising discoveries have been made about the imprint of cultural evolution in the predispositions of human minds for cultural transmission. PMID:21357216

  19. Culture evolves.

    PubMed

    Whiten, Andrew; Hinde, Robert A; Laland, Kevin N; Stringer, Christopher B

    2011-04-12

    Culture pervades human lives and has allowed our species to create niches all around the world and its oceans, in ways quite unlike any other primate. Indeed, our cultural nature appears so distinctive that it is often thought to separate humanity from the rest of nature and the Darwinian forces that shape it. A contrary view arises through the recent discoveries of a diverse range of disciplines, here brought together to illustrate the scope of a burgeoning field of cultural evolution and to facilitate cross-disciplinary fertilization. Each approach emphasizes important linkages between culture and evolutionary biology rather than quarantining one from the other. Recent studies reveal that processes important in cultural transmission are more widespread and significant across the animal kingdom than earlier recognized, with important implications for evolutionary theory. Recent archaeological discoveries have pushed back the origins of human culture to much more ancient times than traditionally thought. These developments suggest previously unidentified continuities between animal and human culture. A third new array of discoveries concerns the later diversification of human cultures, where the operations of Darwinian-like processes are identified, in part, through scientific methods borrowed from biology. Finally, surprising discoveries have been made about the imprint of cultural evolution in the predispositions of human minds for cultural transmission.

  20. H9N2 influenza viruses isolated from poultry in Korean live bird markets continuously evolve and cause the severe clinical signs in layers.

    PubMed

    Kim, Jin A; Cho, Sung Hwan; Kim, Hyun Soo; Seo, Sang Heui

    2006-12-20

    H9N2 influenza viruses are endemic in many Asian countries. We demonstrated that H9N2 influenza viruses isolated from poultry in Korean live bird markets are genetically changing and could cause the clinical signs in layers. Genetic analysis showed that Korean avian H9N2 influenza viruses are distinct from H9N2 influenza viruses circulating in poultry in China and Hong Kong. When we infected layers with H9N2 isolates, layers showed about 30% mortality and the reduction of egg productions. Considering that H9N2 influenza virus is one of potential pandemic candidates, the continuous surveillance is needed to monitor avian H9N2 influenza viruses for the poultry industry and humans.

  1. Natural heterogeneity and evolving geochemistry of Lower Tuscaloosa Formation brine in response to continuing CO2 injection at Cranfield EOR site, Mississippi, USA

    NASA Astrophysics Data System (ADS)

    Thordsen, J. J.; Kharaka, Y. K.; Thomas, B.; Abedini, A. A.; Conaway, C. H.; Manning, M. A.; Lu, J.

    2012-12-01

    Geochemical monitoring of Lower Tuscaloosa Formation (LTF) brine continues at the Cranfield CO2-enhanced oil recovery (EOR) and sequestration site to investigate the potential for the geologic storage of large volumes of CO2 in saline aquifers and depleted reservoirs. Cranfield oil field is a domal depleted oil and gas reservoir in the Mississippi Interior Salt Basin, with production in heterogeneous fluvial sandstones of the LTF (depth ~3000 m). CO2 flood began in July 2008. Brine samples were collected from selected production wells in March and December 2009, April 2010, and November 2011. Intensive sampling also was conducted for the first 18 days of a CO2 injection experiment below the oil-water contact (December 2009) at the Detailed Area of Study (DAS) 3-well array. The sampling objectives are to define the geochemical composition of the pre-injection brine, and to understand the geochemical changes resulting from interactions between the injected CO2, brine, and reservoir minerals. Results show that Tuscaloosa brine is Na-Ca-Cl type with total salinity ranging from ~140 to 160 g/L TDS (50 samples). Relatively large variations are observed in major divalent cations (Ca ~7,500-14,000 mg/L, Mg ~800-1,250 mg/L, Sr ~475-750 mg/L). Significant positive correlations are noted amongst Ca, Mg, Sr, Ba, and Br, whereas these solutes all trend negatively with Na and Cl. These results may be interpreted as possible binary mixing between two end-member waters: (1) high Na-Cl (51 and 97 g/L, respectively), low Ca, Mg, Sr, and Br (~7500, 800, 475, 280 mg/L, respectively); and (2) low Na-Cl (40 and 86 g/L), high Ca, Mg, Sr, and Br (~14,000, 1250, 750, 480 mg/L). This apparent binary mixing has no obvious correlation to CO2 injection, which suggests that observed variations are due to natural heterogeneities in LTF brine within the Cranfield dome. The variations may indicate vertical and/or lateral proximity to a halite source (i.e. salt dome), with the high Na-Cl, low Br

  2. Evolvable Neural Software System

    NASA Technical Reports Server (NTRS)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  3. eta Carinae Continues to Evolve (Abstract)

    NASA Astrophysics Data System (ADS)

    Martin, J. C.

    2015-06-01

    (Abstract only) Eta Carinae affords us a unique opportunity to study the pre-supernova evolution of the most massive stars. For at least the last half century, it has maintained a 5.5-year spectroscopic cycle that culminates with abrupt decreases in the strong stellar wind emission features. Over the last 15 years, the star has brightened at an accelerated rate and altered its spectrum, in addition to the spectroscopic cycle, indicating an ongoing change in state. We present Hubble Space Telescope spectroscopy and synthetic photometry from the most recent spectroscopic event (2014.5) that shows notable differences with past events and provides clues to the on-going evolution of the star.

  4. Best of Breed

    NASA Technical Reports Server (NTRS)

    Lohn, Jason

    2004-01-01

    No team of engineers, no matter how much time they took or how many bottles of cabernet they consumed, would dream up an antenna that looked like a deer antler on steroids. Yet that's what a group at NASA Ames Research Center came up with-thanks to a little help from Darwin. NASA's Space Technology 5 nanosatellites, which are scheduled to start measuring Earth's magnetosphere in late 2004, requires an antenna that can receive a wide range of frequencies regardless of the spacecraft's orientation. Rather than leave such exacting requirements in the hands of a human, the engineers decided to breed a design using genetic algorithms and 32 Linux PCs. The computers generated small antenna-constructing programs (the genotypes) and executed them to produce designs (the phenotypes). Then the designs were evaluated using an antenna simulator. The team settled on the form pictured here. You won't find this kind of antenna in any textbook, design guide, or research paper. But its innovative structure meets a challenging set of specifications. If successfully deployed, it will be the first evolved antenna to make it out of the lab and the first piece of evolved hardware ever to fly in space.

  5. Best of Breed

    NASA Technical Reports Server (NTRS)

    Lohn, Jason

    2004-01-01

    No team of engineers, no matter how much time they took or how many bottles of cabernet they consumed, would dream up an antenna that looked like a deer antler on steroids. Yet that's what a group at NASA Ames Research Center came up with-thanks to a little help from Darwin. NASA's Space Technology 5 nanosatellites, which are scheduled to start measuring Earth's magnetosphere in late 2004, requires an antenna that can receive a wide range of frequencies regardless of the spacecraft's orientation. Rather than leave such exacting requirements in the hands of a human, the engineers decided to breed a design using genetic algorithms and 32 Linux PCs. The computers generated small antenna-constructing programs (the genotypes) and executed them to produce designs (the phenotypes). Then the designs were evaluated using an antenna simulator. The team settled on the form pictured here. You won't find this kind of antenna in any textbook, design guide, or research paper. But its innovative structure meets a challenging set of specifications. If successfully deployed, it will be the first evolved antenna to make it out of the lab and the first piece of evolved hardware ever to fly in space.

  6. Effect of continuous female exposure on behavioral repertoire and stereotypical behaviors in restrained male dromedary camels during the onset of the breeding season.

    PubMed

    Fatnassi, Meriem; Padalino, Barbara; Monaco, David; Khorchani, Touhami; Lacalandra, Giovanni Michele; Hammadi, Mohamed

    2016-06-01

    This study aimed to test the effects of the three management systems on the behavioral repertoire and particularly on the incidence of stereotypical behavior in restrained camels. Five male camels were tested under the following management systems: (i) unexposed, housing in a single box (Unexpo); (ii) continuous exposure, exposed continuously to females (ConExpoF); and (iii) re-unexposed, housing again in a single box (Re-Unexpo). Every day, bulls were filmed for 30 min and videos were analyzed using a focal animal sampling ethogram. Under the ConExpoF system, camels spent the majority of time in standing with opened legs (490.0 ± 94.3 s), looking (925.0 ± 93.7 s), and walking toward the females (206.0 ± 73.4 s) and they ate and ruminated less compared to Unexpo and Re-Unexpo systems. Rumination and standing durations were significantly longer in Re-Unexpo than in Unexpo and ConExpoF management systems. When camels were continuously exposed to females, they showed few stereotypical behaviors compared to Unexpo (490.0 ± 146.1 s) and Re-Unexpo (624.0 ± 146.1 s) systems. The frequency of both total and oral stereotypes was significantly higher in Unexpo and Re-Unexpo systems compared to ConExpoF; however, no significant difference was observed among the three management systems in the frequency of locomotor stereotypes. Overall, it appears that the continuous female exposure system might be a suitable management practice for male camels used for intensive reproduction, as it decreases the manifestation of stereotypical behavior in comparison with housing for 24 h in a single box.

  7. Temporal flexibility of reproduction in temperate-breeding dabbling ducks

    USGS Publications Warehouse

    Krapu, Gary L.

    2000-01-01

    I compared nesting intervals during three consecutive years in five species of temperate-nesting dabbling ducks (Mallard [Anas platyrhynchos], Northern Pintail [Anas acuta], Northern Shoveler [Anas clypeata], Blue-winged Teal [Anas discors], Gadwall [Anas strepera]) and assessed whether differences existed in timing of refractoriness. Most nesting by females of all five species ended by the summer solstice. Nesting ended earliest for Northern Shovelers and Northern Pintails and latest for Gadwalls. Some Mallards, Blue-winged Teal, and Gadwalls continued to nest into mid- and late summer, whereas Northern Shovelers and Northern pintails did not. Mallards, Blue-winged Teal, and Gadwalls accounted for 99% (81 of 82) of flightless broods resulting from nests initiated during mid- or late summer in North Dakota and 98% (58 of 59) of flightless juveniles shot on or after 1 October by a random sample of duck hunters from across the United States. Early cessation of breeding by Northern Shovelers may have evolved in response to the species' limited flexibility in diet. Photorefractory mechanisms that limit most breeding to spring presumably evolved in response to severe constraints on reproductive success when nesting continued through summer(e.g. mortality of late-hatched young and molting females due to low temperatures). Interspecific differences in photosensitivity may account for variation in timing of cessation of nesting in late spring, but controlled experiments are needed to assess the possible role of non-photic influences. My results suggest that the refractory mechanisms controlling length of the breeding in temperate-nesting dabbling ducks are more varied and complex than previously thought, with non-photic influences (e.g. water conditions, food availability, food quality) having a larger role than indicated by earlier research.

  8. Evolvable synthetic neural system

    NASA Technical Reports Server (NTRS)

    Curtis, Steven A. (Inventor)

    2009-01-01

    An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

  9. USDA lettuce breeding and genetics

    USDA-ARS?s Scientific Manuscript database

    The lettuce industry of California requires continued development of improved, adapted cultivars to meet new disease and insect problems, changes in the market, and changes in growing procedures. The USDA lettuce breeding and genetics project aims to incorporate valuable traits into crisphead, mixed...

  10. Diet of canvasbacks during breeding

    USGS Publications Warehouse

    Austin, J.E.; Serie, J.R.; Noyes, J.H.

    1990-01-01

    We examined diets of canvasbacks (Aythya valisineria) breeding in southwestern Manitoba during 1977-81. Percent volume of animal foods consumed did not differ between males and females nor among prenesting, rapid follicle growth, laying, incubation, and renesting periods in females (mean = 50.1%). Tubers and shoots of fennelleaf pondweed (Potamogeton pectinatus) and midge larvae (Chironomidae) were the predominant foods, comprising on average 45% and 23% of the diet volume, respectively. Continued importance of plant foods to canvasbacks throughout reproduction contrasts with the mostly invertebrate diets of other prairie-breeding ducks, and does not fit current theories of nutritional ecology of breeding anatids (i.e., females meet the protein requirements of reproduction by consuming a high proportion of animal foods).

  11. Tritium breeding in fusion reactors

    SciTech Connect

    Abdou, M.A.

    1982-10-01

    Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements.

  12. Advances in Japanese pear breeding in Japan.

    PubMed

    Saito, Toshihiro

    2016-01-01

    The Japanese pear (Pyrus pyrifolia Nakai) is one of the most widely grown fruit trees in Japan, and it has been used throughout Japan's history. The commercial production of pears increased rapidly with the successive discoveries of the chance seedling cultivars 'Chojuro' and 'Nijisseiki' around 1890, and the development of new cultivars has continued since 1915. The late-maturing, leading cultivars 'Niitaka' and 'Shinko' were released during the initial breeding stage. Furthermore, systematic breeding by the Horticultural Research Station (currently, NARO Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NIFTS)) began in 1935, which mainly aimed to improve fruit quality by focusing on flesh texture and black spot disease resistance. To date, 22 cultivars have been released, including 'Kosui', 'Hosui', and 'Akizuki', which are current leading cultivars from the breeding program. Four induced mutant cultivars induced by gamma irradiation, which exhibit some resistance to black spot disease, were released from the Institute of Radiation Breeding. Among these cultivars, 'Gold Nijisseiki' has become a leading cultivar. Moreover, 'Nansui' from the Nagano prefectural institute breeding program was released, and it has also become a leading cultivar. Current breeding objectives at NIFTS mainly combine superior fruit quality with traits related to labor and cost reduction, multiple disease resistance, or self-compatibility. Regarding future breeding, marker-assisted selection for each trait, QTL analyses, genome-wide association studies, and genomic selection analyses are currently in progress.

  13. Sexual Reproduction and Breeding

    USDA-ARS?s Scientific Manuscript database

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  14. Tritium breeding materials

    SciTech Connect

    Hollenberg, G.W.; Johnson, C.E.; Abdou, M.

    1984-03-01

    Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved.

  15. Breeding and genetic diversity

    USDA-ARS?s Scientific Manuscript database

    Corn breeding has been historically remarkably successful. Much research has investigated optimal breeding procedures, which are detailed here. A smaller effort has been put into identifying useful genetic resources for maize and how to best use them, but results from long-term base broadening effor...

  16. Breeding bird communities

    Treesearch

    Vanessa L. Artman; Randy Dettmers

    2003-01-01

    Prescribed burning is being applied on an experimental basis to restore and maintain mixed-oak communities in southern Ohio. This chapter describes baseline conditions for the breeding bird community prior to prescribed burning. We surveyed breeding bird populations at four study areas using the territory-mapping method. We observed 35 bird species during the surveys....

  17. Genomic medicine: evolving science, evolving ethics

    PubMed Central

    Soden, Sarah E; Farrow, Emily G; Saunders, Carol J; Lantos, John D

    2012-01-01

    Genomic medicine is rapidly evolving. Next-generation sequencing is changing the diagnostic paradigm by allowing genetic testing to be carried out more quickly, less expensively and with much higher resolution; pushing the envelope on existing moral norms and legal regulations. Early experience with implementation of next-generation sequencing to diagnose rare genetic conditions in symptomatic children suggests ways that genomic medicine might come to be used and some of the ethical issues that arise, impacting test design, patient selection, consent, sequencing analysis and communication of results. The ethical issues that arise from use of new technologies cannot be satisfactorily analyzed until they are understood and they cannot be understood until the technologies are deployed in the real world. PMID:23173007

  18. Can non-breeding be a cost of breeding dispersal?

    USGS Publications Warehouse

    Danchin, E.; Cam, E.

    2002-01-01

    Breeding habitat selection and dispersal are crucial processes that affect many components of fitness. Breeding dispersal entails costs, one of which has been neglected: dispersing animals may miss breeding opportunities because breeding dispersal requires finding a new nesting site and mate, two time- and energy-consuming activities. Dispersers are expected to be prone to non-breeding. We used the kittiwake (Rissa tridactyla) to test whether breeding dispersal influences breeding probability. Breeding probability was associated with dispersal, in that both were negatively influenced by private information (previous individual reproductive success) and public information (average reproductive success of conspecifics) about patch quality. Furthermore, the probability of skipping breeding was 1.7 times higher in birds that settled in a new patch relative to those that remained on the same patch. Finally, non-breeders that resumed breeding were 4.4 times more likely to disperse than birds that bred in successive years. Although private information may influence breeding probability directly, the link between breeding probability and public information may be indirect, through the influence of public information on breeding dispersal, non-breeding thus being a cost of dispersal. These results support the hypothesis that dispersal may result in not being able to breed. More generally, non-breeding (which can be interpreted as an extreme form of breeding failure) may reveal costs of various previous activities. Because monitoring the non-breeding portion of a population is difficult, non-breeders have been neglected in many studies of reproduction trade-offs.

  19. D-loop haplotype diversity in Brazilian horse breeds

    PubMed Central

    Ianella, Patrícia; Albuquerque, Maria do Socorro Maués; Paiva, Samuel Rezende; do Egito, Andréa Alves; Almeida, Leonardo Daniel; Sereno, Fabiana T. P. S.; Carvalho, Luiz Felipe Ramos; Mariante, Arthur da Silva; McManus, Concepta Margaret

    2017-01-01

    Abstract The first horses were brought to Brazil by the colonizers after 1534. Over the centuries, these animals evolved and adapted to local environmental conditions usually unsuitable for exotic breeds, thereby originating locally adapted Brazilian breeds. The present work represents the first description of maternal genetic diversity in these horse breeds based on D-loop sequences. A D-Loop HSV-I fragment of 252 bp, from 141 horses belonging to ten Brazilian breeds / genetic groups (locally adapted and specialized breeds) were analysed. Thirty-five different haplotypes belonging to 18 haplogroups were identified with 33 polymorphic sites. Haplotype diversity (varying from 0.20 to 0.96) and nucleotide diversity (varying from 0.0039 to 0.0239) was lower for locally adapted than for specialized breeds, with the same pattern observed for FST values. Haplogroups identified in Brazilian breeds are in agreement with previous findings in South American samples. The low variability observed mainly in locally adapted breeds, indicates that, to ensure conservation of these breeds, careful reproductive management is needed. Additional genetic characterization studies are required to support accurate decision-making. PMID:28863209

  20. D-loop haplotype diversity in Brazilian horse breeds.

    PubMed

    Ianella, Patrícia; Albuquerque, Maria do Socorro Maués; Paiva, Samuel Rezende; Egito, Andréa Alves do; Almeida, Leonardo Daniel; Sereno, Fabiana T P S; Carvalho, Luiz Felipe Ramos; Mariante, Arthur da Silva; McManus, Concepta Margaret

    2017-01-01

    The first horses were brought to Brazil by the colonizers after 1534. Over the centuries, these animals evolved and adapted to local environmental conditions usually unsuitable for exotic breeds, thereby originating locally adapted Brazilian breeds. The present work represents the first description of maternal genetic diversity in these horse breeds based on D-loop sequences. A D-Loop HSV-I fragment of 252 bp, from 141 horses belonging to ten Brazilian breeds / genetic groups (locally adapted and specialized breeds) were analysed. Thirty-five different haplotypes belonging to 18 haplogroups were identified with 33 polymorphic sites. Haplotype diversity (varying from 0.20 to 0.96) and nucleotide diversity (varying from 0.0039 to 0.0239) was lower for locally adapted than for specialized breeds, with the same pattern observed for FST values. Haplogroups identified in Brazilian breeds are in agreement with previous findings in South American samples. The low variability observed mainly in locally adapted breeds, indicates that, to ensure conservation of these breeds, careful reproductive management is needed. Additional genetic characterization studies are required to support accurate decision-making.

  1. Small range and distinct distribution in a satellite breeding colony of the critically endangered Waved Albatross

    EPA Science Inventory

    To determine the proximate consequences of the limited breeding distribution of the critically endangered Waved Albatross (Phoebastria irrorata), we present continuous breeding season GPS tracks highlighting differences in behaviour, destinations, and distances travelled between ...

  2. Small range and distinct distribution in a satellite breeding colony of the critically endangered Waved Albatross

    EPA Science Inventory

    To determine the proximate consequences of the limited breeding distribution of the critically endangered Waved Albatross (Phoebastria irrorata), we present continuous breeding season GPS tracks highlighting differences in behaviour, destinations, and distances travelled between ...

  3. Methods Evolved by Observation

    ERIC Educational Resources Information Center

    Montessori, Maria

    2016-01-01

    Montessori's idea of the child's nature and the teacher's perceptiveness begins with amazing simplicity, and when she speaks of "methods evolved," she is unveiling a methodological system for observation. She begins with the early childhood explosion into writing, which is a familiar child phenomenon that Montessori has written about…

  4. Welfare in horse breeding

    PubMed Central

    Campbell, M. L. H.; Sandøe, P.

    2015-01-01

    Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations. PMID:25908746

  5. What drives cooperative breeding?

    PubMed

    Koenig, Walter D

    2017-06-01

    Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

  6. Effect of sex, age, and breed on genetic recombination features in cattle

    USDA-ARS?s Scientific Manuscript database

    Meiotic recombination is a fundamental biological process which generates genetic diversity, affects fertility, and influences evolvability. Here we investigate the roles of sex, age, and breed in cattle recombination features, including recombination rate, location and crossover interference. Usin...

  7. Self Evolving Modular Network

    NASA Astrophysics Data System (ADS)

    Tokunaga, Kazuhiro; Kawabata, Nobuyuki; Furukawa, Tetsuo

    We propose a novel modular network called the Self-Evolving Modular Network (SEEM). The SEEM has a modular network architecture with a graph structure and these following advantages: (1) new modules are added incrementally to allow the network to adapt in a self-organizing manner, and (2) graph's paths are formed based on the relationships between the models represented by modules. The SEEM is expected to be applicable to evolving functions of an autonomous robot in a self-organizing manner through interaction with the robot's environment and categorizing large-scale information. This paper presents the architecture and an algorithm for the SEEM. Moreover, performance characteristic and effectiveness of the network are shown by simulations using cubic functions and a set of 3D-objects.

  8. Guayule: Culture, breeding and rubber production

    USDA-ARS?s Scientific Manuscript database

    Pressure on worldwide Hevea rubber supplies and other factors are renewing interest in guayule rubber. The objective of this chapter is to review recent and past research dealing with guayule production, breeding, and product development. Production research continues to show that although guayule i...

  9. Breeding implications resulting from classification of patellae luxation in dogs.

    PubMed

    van Grevenhof, E M; Hazewinkel, H A W; Heuven, H C M

    2016-08-01

    Patellar luxation (PL) is one of the major hereditary orthopaedic abnormalities observed in a variety of dog breeds. When the patellae move sideways out of the trochlear groove, this is called PL. The PL score varies between dogs from normal to very severe. Reducing the prevalence of PL by breeding could prevent surgery, thereby improve welfare. Orthopaedic specialists differentiate between normal and loose patellae, where the patellae can be moved to the edge of the trochlear groove, considering scoring loose patellae as normal in the future. Loose patellae are considered acceptable for breeding so far by the breeding organization. The aim of this study was to analyse the genetic background of PL to decide on the importance of loose patellae when breeding for healthy dogs. Data are available from two dog breeds, that is Flat-coated Retrievers (n = 3808) and Kooiker dogs (n = 794), with a total of 4602 dogs. Results show that loose patellae indicate that dogs are genetically more susceptible to develop PL because family members of the dogs with loose patellae showed more severe PL. In addition, the estimated breeding values for dogs with loose patellae indicate that breeding values of dogs with loose patellae were worse than breeding values obtained for dogs with a normal score. Given these results, it is advised to orthopaedic specialists to continue to score loose patellae as a separate class and to dog breeders to minimize the use of dogs in breeding with a genetically higher susceptibility for PL.

  10. Challenges and opportunities in genetic improvement of local livestock breeds

    PubMed Central

    Biscarini, Filippo; Nicolazzi, Ezequiel L.; Stella, Alessandra; Boettcher, Paul J.; Gandini, Gustavo

    2015-01-01

    Sufficient genetic variation in livestock populations is necessary both for adaptation to future changes in climate and consumer demand, and for continual genetic improvement of economically important traits. Unfortunately, the current trend is for reduced genetic variation, both within and across breeds. The latter occurs primarily through the loss of small, local breeds. Inferior production is a key driver for loss of small breeds, as they are replaced by high-output international transboundary breeds. Selection to improve productivity of small local breeds is therefore critical for their long term survival. The objective of this paper is to review the technology options available for the genetic improvement of small local breeds and discuss their feasibility. Most technologies have been developed for the high-input breeds and consequently are more favorably applied in that context. Nevertheless, their application in local breeds is not precluded and can yield significant benefits, especially when multiple technologies are applied in close collaboration with farmers and breeders. Breeding strategies that require cooperation and centralized decision-making, such as optimal contribution selection, may in fact be more easily implemented in small breeds. PMID:25763010

  11. Breeding-assisted genomics.

    PubMed

    Poland, Jesse

    2015-04-01

    The revolution of inexpensive sequencing has ushered in an unprecedented age of genomics. The promise of using this technology to accelerate plant breeding is being realized with a vision of genomics-assisted breeding that will lead to rapid genetic gain for expensive and difficult traits. The reality is now that robust phenotypic data is an increasing limiting resource to complement the current wealth of genomic information. While genomics has been hailed as the discipline to fundamentally change the scope of plant breeding, a more symbiotic relationship is likely to emerge. In the context of developing and evaluating large populations needed for functional genomics, none excel in this area more than plant breeders. While genetic studies have long relied on dedicated, well-structured populations, the resources dedicated to these populations in the context of readily available, inexpensive genotyping is making this philosophy less tractable relative to directly focusing functional genomics on material in breeding programs. Through shifting effort for basic genomic studies from dedicated structured populations, to capturing the entire scope of genetic determinants in breeding lines, we can move towards not only furthering our understanding of functional genomics in plants, but also rapidly improving crops for increased food security, availability and nutrition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Simulation of charge breeding of rubidium using Monte Carlo charge breeding code and generalized ECRIS model

    SciTech Connect

    Zhao, L.; Cluggish, B.; Kim, J. S.; Pardo, R.; Vondrasek, R.

    2010-02-15

    A Monte Carlo charge breeding code (MCBC) is being developed by FAR-TECH, Inc. to model the capture and charge breeding of 1+ ion beam in an electron cyclotron resonance ion source (ECRIS) device. The ECRIS plasma is simulated using the generalized ECRIS model which has two choices of boundary settings, free boundary condition and Bohm condition. The charge state distribution of the extracted beam ions is calculated by solving the steady state ion continuity equations where the profiles of the captured ions are used as source terms. MCBC simulations of the charge breeding of Rb+ showed good agreement with recent charge breeding experiments at Argonne National Laboratory (ANL). MCBC correctly predicted the peak of highly charged ion state outputs under free boundary condition and similar charge state distribution width but a lower peak charge state under the Bohm condition. The comparisons between the simulation results and ANL experimental measurements are presented and discussed.

  13. The Evolving Office of the Registrar

    ERIC Educational Resources Information Center

    Pace, Harold L.

    2011-01-01

    A healthy registrar's office will continue to evolve as it considers student, faculty, and institutional needs; staff talents and expectations; technological opportunities; economic realities; space issues; work environments; and where the strategic plan is taking the institution in support of the mission. Several recognized leaders in the field…

  14. Highly-evolved stars

    NASA Technical Reports Server (NTRS)

    Heap, S. R.

    1981-01-01

    The ways in which the IUE has proved useful in studying highly evolved stars are reviewed. The importance of high dispersion spectra for abundance analyses of the sd0 stars and for studies of the wind from the central star of NGC 6543 and the wind from the 0 type component of Vela X-1 is shown. Low dispersion spectra are used for absolute spectrophotometry of the dwarf nova, Ex Hya. Angular resolution is important for detecting and locating UV sources in globular clusters.

  15. Regolith Evolved Gas Analyzer

    NASA Technical Reports Server (NTRS)

    Hoffman, John H.; Hedgecock, Jud; Nienaber, Terry; Cooper, Bonnie; Allen, Carlton; Ming, Doug

    2000-01-01

    The Regolith Evolved Gas Analyzer (REGA) is a high-temperature furnace and mass spectrometer instrument for determining the mineralogical composition and reactivity of soil samples. REGA provides key mineralogical and reactivity data that is needed to understand the soil chemistry of an asteroid, which then aids in determining in-situ which materials should be selected for return to earth. REGA is capable of conducting a number of direct soil measurements that are unique to this instrument. These experimental measurements include: (1) Mass spectrum analysis of evolved gases from soil samples as they are heated from ambient temperature to 900 C; and (2) Identification of liberated chemicals, e.g., water, oxygen, sulfur, chlorine, and fluorine. REGA would be placed on the surface of a near earth asteroid. It is an autonomous instrument that is controlled from earth but does the analysis of regolith materials automatically. The REGA instrument consists of four primary components: (1) a flight-proven mass spectrometer, (2) a high-temperature furnace, (3) a soil handling system, and (4) a microcontroller. An external arm containing a scoop or drill gathers regolith samples. A sample is placed in the inlet orifice where the finest-grained particles are sifted into a metering volume and subsequently moved into a crucible. A movable arm then places the crucible in the furnace. The furnace is closed, thereby sealing the inner volume to collect the evolved gases for analysis. Owing to the very low g forces on an asteroid compared to Mars or the moon, the sample must be moved from inlet to crucible by mechanical means rather than by gravity. As the soil sample is heated through a programmed pattern, the gases evolved at each temperature are passed through a transfer tube to the mass spectrometer for analysis and identification. Return data from the instrument will lead to new insights and discoveries including: (1) Identification of the molecular masses of all of the gases

  16. Advances in Japanese pear breeding in Japan

    PubMed Central

    Saito, Toshihiro

    2016-01-01

    The Japanese pear (Pyrus pyrifolia Nakai) is one of the most widely grown fruit trees in Japan, and it has been used throughout Japan’s history. The commercial production of pears increased rapidly with the successive discoveries of the chance seedling cultivars ‘Chojuro’ and ‘Nijisseiki’ around 1890, and the development of new cultivars has continued since 1915. The late-maturing, leading cultivars ‘Niitaka’ and ‘Shinko’ were released during the initial breeding stage. Furthermore, systematic breeding by the Horticultural Research Station (currently, NARO Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NIFTS)) began in 1935, which mainly aimed to improve fruit quality by focusing on flesh texture and black spot disease resistance. To date, 22 cultivars have been released, including ‘Kosui’, ‘Hosui’, and ‘Akizuki’, which are current leading cultivars from the breeding program. Four induced mutant cultivars induced by gamma irradiation, which exhibit some resistance to black spot disease, were released from the Institute of Radiation Breeding. Among these cultivars, ‘Gold Nijisseiki’ has become a leading cultivar. Moreover, ‘Nansui’ from the Nagano prefectural institute breeding program was released, and it has also become a leading cultivar. Current breeding objectives at NIFTS mainly combine superior fruit quality with traits related to labor and cost reduction, multiple disease resistance, or self-compatibility. Regarding future breeding, marker-assisted selection for each trait, QTL analyses, genome-wide association studies, and genomic selection analyses are currently in progress. PMID:27069390

  17. Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies.

    PubMed

    Phocas, F; Belloc, C; Bidanel, J; Delaby, L; Dourmad, J Y; Dumont, B; Ezanno, P; Fortun-Lamothe, L; Foucras, G; Frappat, B; González-García, E; Hazard, D; Larzul, C; Lubac, S; Mignon-Grasteau, S; Moreno, C R; Tixier-Boichard, M; Brochard, M

    2016-11-01

    Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could

  18. Integrating genomics into Eucalyptus breeding.

    PubMed

    Grattapaglia, Dario

    2004-09-30

    The advent of high throughput genomic technologies has opened new perspectives in the speed, scale and detail with which one can investigate genes, genomes and complex traits in Eucalyptus species. A genomic approach to a more detailed understanding of important metabolic and physiological processes, which affect tree growth and stress resistance, and the identification of genes and their allelic variants, which determine the major chemical and physical features of wood properties, should eventually lead to new opportunities for directed genetic modifications of far-reaching economic impact in forest industry. It should be kept in mind, however, that basic breeding strategies, coupled with sophisticated quantitative methods, breeder's experience and breeder's intuition, will continue to generate significant genetic gains and have a clear measurable impact on production forestry. Even with a much more global view of genetic processes, genomics will only succeed in contributing to the development of improved industrial forests if it is strongly interconnected with intensive fieldwork and creative breeding. Integrated genomic projects involving multi-species expressed sequence tag sequencing and quantitative trait locus detection, single nucleotide polymorphism discovery for association mapping, and the development of a gene-rich physical map for the Eucalyptus genome will quickly move toward linking phenotypes to genes that control the wood formation processes that define industrial-level traits. Exploiting the full power of the superior natural phenotypic variation in wood properties found in Eucalyptus genetic resources will undoubtedly be a key factor to reach this goal.

  19. A Stefan problem on an evolving surface

    PubMed Central

    Alphonse, Amal; Elliott, Charles M.

    2015-01-01

    We formulate a Stefan problem on an evolving hypersurface and study the well posedness of weak solutions given L1 data. To do this, we first develop function spaces and results to handle equations on evolving surfaces in order to give a natural treatment of the problem. Then, we consider the existence of solutions for data; this is done by regularization of the nonlinearity. The regularized problem is solved by a fixed point theorem and then uniform estimates are obtained in order to pass to the limit. By using a duality method, we show continuous dependence, which allows us to extend the results to L1 data. PMID:26261364

  20. Lettuce and spinach breeding

    USDA-ARS?s Scientific Manuscript database

    Lettuce and spinach production is beset by numerous biotic an abiotic challenges. This report to the California Leafy Greens Research Program annual meeting provides an update by the ‘Genetic Enhancement of Lettuce, Spinach, Melon, and Related Species’ project at Salinas on the genetics and breeding...

  1. Raspberry Breeding and Genetics

    USDA-ARS?s Scientific Manuscript database

    This chapter describes the origin, speciation, and history of improvement of the raspberries, Rubus section idaeobatus. The world industry in North America, Australasia, China, Europe, Eastern Europe, Africa, and South America and the breeding objectives of programs in those areas are discussed. Ger...

  2. Lettuce and spinach breeding

    USDA-ARS?s Scientific Manuscript database

    Lettuce and spinach production is beset by numerous biotic an abiotic challenges. This report to the California Leafy Greens Research Program annual meeting provides an update by the ‘Genetic Enhancement of Lettuce, Spinach, Melon, and Related Species’ project at Salinas on the genetics and breeding...

  3. Plant breeding and genetics

    USDA-ARS?s Scientific Manuscript database

    The ultimate goal of plant breeding is to develop improved crops. Improvements can be made in crop productivity, crop processing and marketing, and/or consumer quality. The process of developing an improved cultivar begins with intercrossing lines with high performance for the traits of interest, th...

  4. Hop Cultivars and Breeding

    USDA-ARS?s Scientific Manuscript database

    Pest management decision making in hops varies among cultivars. Historically, the primary objective of hop breeding programs has been to increase the yield or characteristics associated with either bittering (high alpha-acids) or aroma (unique volatile oil profiles) cultivars. Other factors consid...

  5. Our evolving universe

    NASA Astrophysics Data System (ADS)

    Longair, Malcolm S.

    Our Evolving Universe is a lucid, non-technical and infectiously enthusiastic introduction to current astronomy and cosmology. Highly illustrated throughout with the latest colour images from the world's most advanced telescopes, it also provides a colourful view of our Universe. Malcolm Longair takes us on a breathtaking tour of the most dramatic recent results astronomers have on the birth of stars, the hunt for black holes and dark matter, on gravitational lensing and the latest tests of the Big Bang. He leads the reader right up to understand the key questions that future research in astronomy and cosmology must answer. A clear and comprehensive glossary of technical terms is also provided. For the general reader, student or professional wishing to understand the key questions today's astronomers and cosmologists are trying to answer, this is an invaluable and inspiring read.

  6. Advances in Diagnostics and Therapeutic Techniques in Breeding Behavior Disorders in Stallions.

    PubMed

    McDonnell, Sue M

    2016-12-01

    Despite the suboptimal aspects of domestic breeding conditions compared with the natural conditions under which their reproductive behavior evolved, most domestic stallions can adapt to management and breeding programs. Most respond adequately or quickly learn to safely abide the restraint and direction of a human handler, and can adapt to changes in methods of breeding for semen collection. If not, the problems can range from inadequate or variable sexual interest and response to overenthusiastic or aggressive response beyond the ability of the handlers to safely direct and control. This article discusses veterinary evaluation as well as housing and handling strategies for addressing stallion breeding behavior problems.

  7. Evolution of evolvability and phenotypic plasticity in virtual cells.

    PubMed

    Cuypers, Thomas D; Rutten, Jacob P; Hogeweg, Paulien

    2017-02-28

    Changing environmental conditions pose a challenge for the survival of species. To meet this challenge organisms adapt their phenotype by physiological regulation (phenotypic plasticity) or by evolving. Regulatory mechanisms that ensure a constant internal environment in the face of continuous external fluctuations (homeostasis) are ubiquitous and essential for survival. However, more drastic and enduring environmental change, often requires lineages to adapt by mutating. In vitro evolutionary experiments with microbes show that adaptive, large phenotypic changes occur remarkably quickly, requiring only a few mutations. It has been proposed that the high evolvability demonstrated by these microbes, is an evolved property. If both regulation (phenotypic plasticity) and evolvability can evolve as strategies to adapt to change, what are the conditions that favour the emergence of either of these strategy? Does evolution of one strategy hinder or facilitate evolution of the other strategy? Here we investigate this with computational evolutionary modelling in populations of Virtual Cells. During a preparatory evolutionary phase, Virtual Cells evolved homeostasis regulation for internal metabolite concentrations in a fluctuating environment. The resulting wild-type Virtual Cell strains (WT-VCS) were then exposed to periodic, drastic environmental changes, while maintaining selection on homeostasis regulation. In different sets of simulations the nature and frequencies of environmental change were varied. Pre-evolved WT-VCS were highly evolvable, showing rapid evolutionary adaptation after novel environmental change. Moreover, continued low frequency changes resulted in evolutionary restructuring of the genome that enables even faster adaptation with very few mutations. In contrast, when change frequency is high, lineages evolve phenotypic plasticity that allows them to be fit in different environments without mutations. Yet, evolving phenotypic plasticity is a

  8. Quantifying evolvability in small biological networks

    SciTech Connect

    Nemenman, Ilya; Mugler, Andrew; Ziv, Etay; Wiggins, Chris H

    2008-01-01

    The authors introduce a quantitative measure of the capacity of a small biological network to evolve. The measure is applied to a stochastic description of the experimental setup of Guet et al. (Science 2002, 296, pp. 1466), treating chemical inducers as functional inputs to biochemical networks and the expression of a reporter gene as the functional output. The authors take an information-theoretic approach, allowing the system to set parameters that optimise signal processing ability, thus enumerating each network's highest-fidelity functions. All networks studied are highly evolvable by the measure, meaning that change in function has little dependence on change in parameters. Moreover, each network's functions are connected by paths in the parameter space along which information is not significantly lowered, meaning a network may continuously change its functionality without completely losing it along the way. This property further underscores the evolvability of the networks.

  9. Why did heterospory evolve?

    PubMed

    Petersen, Kurt B; Burd, Martin

    2016-10-11

    The primitive land plant life cycle featured the production of spores of unimodal size, a condition called homospory. The evolution of bimodal size distributions with small male spores and large female spores, known as heterospory, was an innovation that occurred repeatedly in the history of land plants. The importance of desiccation-resistant spores for colonization of the land is well known, but the adaptive value of heterospory has never been well established. It was an addition to a sexual life cycle that already involved male and female gametes. Its role as a precursor to the evolution of seeds has received much attention, but this is an evolutionary consequence of heterospory that cannot explain the transition from homospory to heterospory (and the lack of evolutionary reversal from heterospory to homospory). Enforced outcrossing of gametophytes has often been mentioned in connection to heterospory, but we review the shortcomings of this argument as an explanation of the selective advantage of heterospory. Few alternative arguments concerning the selective forces favouring heterospory have been proposed, a paucity of attention that is surprising given the importance of this innovation in land plant evolution. In this review we highlight two ideas that may lead us to a better understanding of why heterospory evolved. First, models of optimal resource allocation - an approach that has been used for decades in evolutionary ecology to help understand parental investment and other life-history patterns - suggest that an evolutionary increase in spore size could reach a threshold at which small spores yielding small, sperm-producing gametophytes would return greater fitness per unit of resource investment than would large spores and bisexual gametophytes. With the advent of such microspores, megaspores would evolve under frequency-dependent selection. This argument can account for the appearance of heterospory in the Devonian, when increasingly tall and complex

  10. Evolving a photosynthetic organelle.

    PubMed

    Nakayama, Takuro; Archibald, John M

    2012-04-24

    The evolution of plastids from cyanobacteria is believed to represent a singularity in the history of life. The enigmatic amoeba Paulinella and its 'recently' acquired photosynthetic inclusions provide a fascinating system through which to gain fresh insight into how endosymbionts become organelles.The plastids, or chloroplasts, of algae and plants evolved from cyanobacteria by endosymbiosis. This landmark event conferred on eukaryotes the benefits of photosynthesis--the conversion of solar energy into chemical energy--and in so doing had a huge impact on the course of evolution and the climate of Earth 1. From the present state of plastids, however, it is difficult to trace the evolutionary steps involved in this momentous development, because all modern-day plastids have fully integrated into their hosts. Paulinella chromatophora is a unicellular eukaryote that bears photosynthetic entities called chromatophores that are derived from cyanobacteria and has thus received much attention as a possible example of an organism in the early stages of organellogenesis. Recent studies have unlocked the genomic secrets of its chromatophore 23 and provided concrete evidence that the Paulinella chromatophore is a bona fide photosynthetic organelle 4. The question is how Paulinella can help us to understand the process by which an endosymbiont is converted into an organelle.

  11. Communicability across evolving networks.

    PubMed

    Grindrod, Peter; Parsons, Mark C; Higham, Desmond J; Estrada, Ernesto

    2011-04-01

    Many natural and technological applications generate time-ordered sequences of networks, defined over a fixed set of nodes; for example, time-stamped information about "who phoned who" or "who came into contact with who" arise naturally in studies of communication and the spread of disease. Concepts and algorithms for static networks do not immediately carry through to this dynamic setting. For example, suppose A and B interact in the morning, and then B and C interact in the afternoon. Information, or disease, may then pass from A to C, but not vice versa. This subtlety is lost if we simply summarize using the daily aggregate network given by the chain A-B-C. However, using a natural definition of a walk on an evolving network, we show that classic centrality measures from the static setting can be extended in a computationally convenient manner. In particular, communicability indices can be computed to summarize the ability of each node to broadcast and receive information. The computations involve basic operations in linear algebra, and the asymmetry caused by time's arrow is captured naturally through the noncommutativity of matrix-matrix multiplication. Illustrative examples are given for both synthetic and real-world communication data sets. We also discuss the use of the new centrality measures for real-time monitoring and prediction.

  12. Evolving Concepts of Asthma

    PubMed Central

    Ray, Anuradha; Wenzel, Sally E.

    2015-01-01

    Our understanding of asthma has evolved over time from a singular disease to a complex of various phenotypes, with varied natural histories, physiologies, and responses to treatment. Early therapies treated most patients with asthma similarly, with bronchodilators and corticosteroids, but these therapies had varying degrees of success. Similarly, despite initial studies that identified an underlying type 2 inflammation in the airways of patients with asthma, biologic therapies targeted toward these type 2 pathways were unsuccessful in all patients. These observations led to increased interest in phenotyping asthma. Clinical approaches, both biased and later unbiased/statistical approaches to large asthma patient cohorts, identified a variety of patient characteristics, but they also consistently identified the importance of age of onset of disease and the presence of eosinophils in determining clinically relevant phenotypes. These paralleled molecular approaches to phenotyping that developed an understanding that not all patients share a type 2 inflammatory pattern. Using biomarkers to select patients with type 2 inflammation, repeated trials of biologics directed toward type 2 cytokine pathways saw newfound success, confirming the importance of phenotyping in asthma. Further research is needed to clarify additional clinical and molecular phenotypes, validate predictive biomarkers, and identify new areas for possible interventions. PMID:26161792

  13. Evolving synergetic interactions

    PubMed Central

    Wu, Bin; Arranz, Jordi; Du, Jinming; Zhou, Da; Traulsen, Arne

    2016-01-01

    Cooperators forgo their own interests to benefit others. This reduces their fitness and thus cooperators are not likely to spread based on natural selection. Nonetheless, cooperation is widespread on every level of biological organization ranging from bacterial communities to human society. Mathematical models can help to explain under which circumstances cooperation evolves. Evolutionary game theory is a powerful mathematical tool to depict the interactions between cooperators and defectors. Classical models typically involve either pairwise interactions between individuals or a linear superposition of these interactions. For interactions within groups, however, synergetic effects may arise: their outcome is not just the sum of its parts. This is because the payoffs via a single group interaction can be different from the sum of any collection of two-player interactions. Assuming that all interactions start from pairs, how can such synergetic multiplayer games emerge from simpler pairwise interactions? Here, we present a mathematical model that captures the transition from pairwise interactions to synergetic multiplayer ones. We assume that different social groups have different breaking rates. We show that non-uniform breaking rates do foster the emergence of synergy, even though individuals always interact in pairs. Our work sheds new light on the mechanisms underlying such synergetic interactions. PMID:27466437

  14. Plant breeding on the front: imperialism, war, and exploitation.

    PubMed

    Elina, Olga; Heim, Susanne; Roll-Hansen, Nils

    2005-01-01

    This paper examines the development of plant-breeding science in the context of the booming genetic research and autarky policy of the 1930s as well as during World War II in National Socialist-occupied Europe. Soviet scientists, especially Nikolai Vavilov and his VIR institute, had a leading position in the international plant-breeding science of the 1920s. During World War II, German scientists, namely experts from the Kaiser Wilhelm Institute for Plant Breeding, usurped Soviet institutes and valuable seed collections. In contrast, plant-breeding research in occupied Scandinavia continued with relatively little disturbance. The paper compares behavior of German, Soviet, and Norwegian plant-breeding scientists under the Nazi regime.

  15. Precision animal breeding.

    PubMed

    Flint, A P F; Woolliams, J A

    2008-02-12

    We accept that we are responsible for the quality of life of animals in our care. We accept that the activities of man affect all the living things with which we share this planet. But we are slow to realize that as a result we have a duty of care for all living things. That duty extends to the breeding of animals for which we are responsible. When animals are bred by man for a purpose, the aim should be to meet certain goals: to improve the precision with which breeding outcomes can be predicted; to avoid the introduction and advance of characteristics deleterious to well-being; and to manage genetic resources and diversity between and within populations as set out in the Convention on Biological Diversity. These goals are summed up in the phrase precision animal breeding. They should apply whether animals are bred as sources of usable products or services for medical or scientific research, for aesthetic or cultural considerations, or as pets. Modern molecular and quantitative genetics and advances in reproductive physiology provide the tools with which these goals can be met.

  16. Genetic comparison of breeding schemes based on semen importation and local breeding schemes: framework and application to Costa Rica.

    PubMed

    Vargas, B; van Arendonk, J A M

    2004-05-01

    Local breeding schemes for Holstein cattle of Costa Rica were compared with the current practice based on continuous semen importation (SI) by deterministic simulation. Comparison was made on the basis of genetic response and correlation between breeding goals. A local breeding goal was defined on the basis of prevailing production circumstances and compared against a typical breeding goal for an exporting country. Differences in genetic response were <3%, and the correlation between breeding goals was 0.99. Therefore, difference between breeding objectives proved negligible. For the evaluation of genetic response, the current scheme based on SI was evaluated against a progeny testing (PT) scheme and a closed nucleus (CN) breeding scheme, both local. Selection intensities and accuracy of selection were defined according to current population size and reproduction efficiency parameters. When genotype x environment interaction (G x E) was ignored, SI was the strategy with the highest genetic response: 5.0% above the CN breeding scheme and 33.2% above PT. A correlation between breeding values in both countries lower than one was assumed to assess the effect of G x E. This resulted in permanent effects on the relative efficiencies of breeding strategies because of the reduction in the rate of genetic response when SI was used. When the genetic correlation was assumed equal to 0.75, the genetic response achieved with SI was reduced at the same level as local PT. When an initial difference in average genetic merit of the populations was assumed, this only had a temporal effect on the relative ranking of strategies, which is reverted after some years of selection because the rate of change in genetic responses remains unchanged. Given that the actual levels of genetic correlation between countries may be around 0.60, it was concluded that a local breeding scheme based on a nucleus herd could provide better results than the current strategy based on SI.

  17. Biotechnology and apple breeding in Japan

    PubMed Central

    Igarashi, Megumi; Hatsuyama, Yoshimichi; Harada, Takeo; Fukasawa-Akada, Tomoko

    2016-01-01

    Apple is a fruit crop of significant economic importance, and breeders world wide continue to develop novel cultivars with improved characteristics. The lengthy juvenile period and the large field space required to grow apple populations have imposed major limitations on breeding. Various molecular biological techniques have been employed to make apple breeding easier. Transgenic technology has facilitated the development of apples with resistance to fungal or bacterial diseases, improved fruit quality, or root stocks with better rooting or dwarfing ability. DNA markers for disease resistance (scab, powdery mildew, fire-blight, Alternaria blotch) and fruit skin color have also been developed, and marker-assisted selection (MAS) has been employed in breeding programs. In the last decade, genomic sequences and chromosome maps of various cultivars have become available, allowing the development of large SNP arrays, enabling efficient QTL mapping and genomic selection (GS). In recent years, new technologies for genetic improvement, such as trans-grafting, virus vectors, and genome-editing, have emerged. Using these techniques, no foreign genes are present in the final product, and some of them show considerable promise for application to apple breeding. PMID:27069388

  18. Evolving Indications for Tips.

    PubMed

    Smith, Mitchell; Durham, Janette

    2016-03-01

    Transjugular intrahepatic portosystemic shunt creation is a well-established therapy for refractory variceal bleeding and refractory ascites in patients who do not tolerate repeated large volume paracentesis. Experience and technical improvements including covered stents have led to improved TIPS outcomes that have encouraged an expanded application. Evidence for other less frequent indications continues to accumulate, including the indications of primary prophylaxis in patients with high-risk acute variceal bleeding, gastric and ectopic variceal bleeding, primary treatment of medically refractory ascites, recurrent refractory ascites following liver transplantation, hepatic hydrothorax, hepatorenal syndrome, Budd-Chiari syndrome, and portal vein thrombosis. Treatment of patients with high-risk acute variceal bleeding with early TIPS and using transjugular intrahepatic portosystemic shunts as a primary therapy rather than large volume paracentesis for refractory ascites would likely be the 2 circumstances that permit expansion in the frequency of TIPS procedures. The remaining populations discussed above are relatively rare.

  19. Disgust: Evolved Function and Structure

    ERIC Educational Resources Information Center

    Tybur, Joshua M.; Lieberman, Debra; Kurzban, Robert; DeScioli, Peter

    2013-01-01

    Interest in and research on disgust has surged over the past few decades. The field, however, still lacks a coherent theoretical framework for understanding the evolved function or functions of disgust. Here we present such a framework, emphasizing 2 levels of analysis: that of evolved function and that of information processing. Although there is…

  20. Evolving virtual creatures and catapults.

    PubMed

    Chaumont, Nicolas; Egli, Richard; Adami, Christoph

    2007-01-01

    We present a system that can evolve the morphology and the controller of virtual walking and block-throwing creatures (catapults) using a genetic algorithm. The system is based on Sims' work, implemented as a flexible platform with an off-the-shelf dynamics engine. Experiments aimed at evolving Sims-type walkers resulted in the emergence of various realistic gaits while using fairly simple objective functions. Due to the flexibility of the system, drastically different morphologies and functions evolved with only minor modifications to the system and objective function. For example, various throwing techniques evolved when selecting for catapults that propel a block as far as possible. Among the strategies and morphologies evolved, we find the drop-kick strategy, as well as the systematic invention of the principle behind the wheel, when allowing mutations to the projectile.

  1. Cooperative breeding in oscine passerines: does sociality inhibit speciation?

    PubMed Central

    Cockburn, Andrew

    2003-01-01

    Cooperative breeding in birds is much more prevalent than has been previously realized, occurring in 18.5% of oscine passerines known to have biparental care, and is the predominant social system of some ancient oscine clades. Cooperation is distributed unevenly in clades that contain both cooperative and pair breeders, and is usually confined to a few related genera in which it can be ubiquitous. Cooperative clades are species poor compared with pair-breeding clades, because pair breeders evolve migratory habits, speciate on oceanic islands and are more likely to have distributions spread across more than one biogeographic region. These differences reflect the increased capacity for colonization by pair breeders because their young disperse. Thus cooperative breeding has macroevolutionary consequences by restricting rates of speciation and macroecological implications by influencing the assembly of island and migrant faunas. PMID:14613606

  2. Diversity and Affirmative Action: Evolving Principles and Continuing Legal Battles.

    ERIC Educational Resources Information Center

    Palmer, Scott R.

    This chapter reviews the legal standards governing affirmative action in higher education, examining the diversity rationale and contrasting the cases of Hopwood v. Texas and Wittmer v. Peters, which were decided in 1996. It discusses: the legal standard governing affirmative action in higher education; the remedial interest in overcoming the…

  3. Understanding crop genetic diversity under modern plant breeding.

    PubMed

    Fu, Yong-Bi

    2015-11-01

    Maximizing crop yield while at the same time minimizing crop failure for sustainable agriculture requires a better understanding of the impacts of plant breeding on crop genetic diversity. This review identifies knowledge gaps and shows the need for more research into genetic diversity changes under plant breeding. Modern plant breeding has made a profound impact on food production and will continue to play a vital role in world food security. For sustainable agriculture, a compromise should be sought between maximizing crop yield under changing climate and minimizing crop failure under unfavorable conditions. Such a compromise requires better understanding of the impacts of plant breeding on crop genetic diversity. Efforts have been made over the last three decades to assess crop genetic diversity using molecular marker technologies. However, these assessments have revealed some temporal diversity patterns that are largely inconsistent with our perception that modern plant breeding reduces crop genetic diversity. An attempt was made in this review to explain such discrepancies by examining empirical assessments of crop genetic diversity and theoretical investigations of genetic diversity changes over time under artificial selection. It was found that many crop genetic diversity assessments were not designed to assess diversity impacts from specific plant breeding programs, while others were experimentally inadequate and contained technical biases from the sampling of cultivars and genomes. Little attention has been paid to theoretical investigations on crop genetic diversity changes from plant breeding. A computer simulation of five simplified breeding schemes showed the substantial effects of plant breeding on the retention of heterozygosity over generations. It is clear that more efforts are needed to investigate crop genetic diversity in space and time under plant breeding to achieve sustainable crop production.

  4. Canine Breed-Specific Hepatopathies.

    PubMed

    Watson, Penny

    2017-05-01

    Canine hepatopathies, both congenital and acquired, arise from an interaction between genes and environment. Many show increased breed prevalences. This article reviews the current understanding on breed predispositions for congenital portosystemic shunts; microvascular dysplasia and portal vein hypoplasia; ductal plate abnormalities (congenital hepatic fibrosis and Caroli disease); chronic hepatitis (both copper associated and idiopathic); vacuolar hepatopathies; and gallbladder mucocele. Although all these diseases can occur in many breeds and crossbreeds, understanding breed predispositions helps recognition and will guide future research to improve understanding of causes and treatments. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  5. RosBREED: Enabling Marker-Assisted Breeding In Rosaceae

    USDA-ARS?s Scientific Manuscript database

    RosBREED will create a national, dynamic, sustained effort in research, infrastructure establishment, training, and extension for applying marker-assisted breeding (MAB) to deliver improved plant materials more efficiently and rapidly. The Rosaceae family (including apple, peach, sweet and tart cher...

  6. Idiopathic pulmonary fibrosis: evolving concepts.

    PubMed

    Ryu, Jay H; Moua, Teng; Daniels, Craig E; Hartman, Thomas E; Yi, Eunhee S; Utz, James P; Limper, Andrew H

    2014-08-01

    Idiopathic pulmonary fibrosis (IPF) occurs predominantly in middle-aged and older adults and accounts for 20% to 30% of interstitial lung diseases. It is usually progressive, resulting in respiratory failure and death. Diagnostic criteria for IPF have evolved over the years, and IPF is currently defined as a disease characterized by the histopathologic pattern of usual interstitial pneumonia occurring in the absence of an identifiable cause of lung injury. Understanding of the pathogenesis of IPF has shifted away from chronic inflammation and toward dysregulated fibroproliferative repair in response to alveolar epithelial injury. Idiopathic pulmonary fibrosis is likely a heterogeneous disorder caused by various interactions between genetic components and environmental exposures. High-resolution computed tomography can be diagnostic in the presence of typical findings such as bilateral reticular opacities associated with traction bronchiectasis/bronchiolectasis in a predominantly basal and subpleural distribution, along with subpleural honeycombing. In other circumstances, a surgical lung biopsy may be needed. The clinical course of IPF can be unpredictable and may be punctuated by acute deteriorations (acute exacerbation). Although progress continues in unraveling the mechanisms of IPF, effective therapy has remained elusive. Thus, clinicians and patients need to reach informed decisions regarding management options including lung transplant. The findings in this review were based on a literature search of PubMed using the search terms idiopathic pulmonary fibrosis and usual interstitial pneumonia, limited to human studies in the English language published from January 1, 2000, through December 31, 2013, and supplemented by key references published before the year 2000. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  7. Developments in European horse breeding and consequences for veterinarians in equine reproduction.

    PubMed

    Aurich, J; Aurich, C

    2006-08-01

    The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled-transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low-dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad-intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.

  8. Survival of the fastest: Evolving wings for flapping flight

    NASA Astrophysics Data System (ADS)

    Ramananarivo, Sophie; Mitchel, Thomas; Ristroph, Leif

    2014-11-01

    To optimize flapping flight with regard to wing shape, we use an evolutionary or genetic algorithm to improve the forward speed of 3d-printed wings or hydrofoils that heave up-and-down and self-propel within water. In this scheme, ``genes'' are mathematical parameters specifying wing shape, and ``breeding'' involves the merging and mutation of genes from two parent wings to form a child. A wing's swimming speed is its ``fitness'', which dictates the likelihood of breeding and thus passing on its genes to the next generation. We find that this iterative process leads to marked improvements in relatively few generations, and several distinct shape features are shared among the fastest wings. We also investigate the favorable flow structures produced by these elite swimmers and compare their shape and performance to biologically evolved wings, fins, tails, and flippers.

  9. ITER breeding blanket design

    SciTech Connect

    Gohar, Y.; Cardella, A.; Ioki, K.; Lousteau, D.; Mohri, K.; Raffray, R.; Zolti, E.

    1995-12-31

    A breeding blanket design has been developed for ITER to provide the necessary tritium fuel to achieve the technical objectives of the Enhanced Performance Phase. It uses a ceramic breeder and water coolant for compatibility with the ITER machine design of the Basic Performance Phase. Lithium zirconate and lithium oxide am the selected ceramic breeders based on the current data base. Enriched lithium and beryllium neutron multiplier are used for both breeders. Both forms of beryllium material, blocks and pebbles are used at different blanket locations based on thermo-mechanical considerations and beryllium thickness requirements. Type 316LN austenitic steel is used as structural material similar to the shielding blanket. Design issues and required R&D data are identified during the development of the design.

  10. Breeding cassava for higher yield

    USDA-ARS?s Scientific Manuscript database

    Cassava is a root crop grown for food and for starch production. Breeding progress is slowed by asexual production and high levels of heterozygosity. Germplasm resources are rich and accessible to breeders through genebanks worldwide. Breeding objectives include high root yield, yield stability, dis...

  11. Persian walnut breeding in California

    Treesearch

    Charles A. Leslie; Gale H. McGranahan

    2004-01-01

    For over 50 years the University of California Davis Walnut Breeding Program has worked to address the needs of California walnut growers by identifying genetic approaches to problems and developing improved cultivars. The breeding program is a cooperative endeavor that draws on the efforts and resources of university researchers and facilities, USDA germplasm programs...

  12. Radiation-induced mutations and plant breeding

    SciTech Connect

    Naqvi, S.H.M.

    1985-01-01

    Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far.

  13. How did the cilium evolve?

    PubMed

    Satir, Peter; Mitchell, David R; Jékely, Gáspár

    2008-01-01

    The cilium is a characteristic organelle of eukaryotes constructed from over 600 proteins. Bacterial flagella are entirely different. 9 + 2 motile cilia evolved before the divergence of the last eukaryotic common ancestor (LECA). This chapter explores, compares, and contrasts two potential pathways of evolution: (1) via invasion of a centriolar-like virus and (2) via autogenous formation from a pre-existing microtubule-organizing center (MTOC). In either case, the intraflagellar transport (IFT) machinery that is nearly universally required for the assembly and maintenance of cilia derived from the evolving intracellular vesicular transport system. The sensory function of cilia evolved first and the ciliary axoneme evolved gradually with ciliary motility, an important selection mechanism, as one of the driving forces.

  14. Cooperative breeding in South American hunter–gatherers

    PubMed Central

    Hill, Kim; Hurtado, A. Magdalena

    2009-01-01

    Evolutionary researchers have recently suggested that pre-modern human societies habitually practised cooperative breeding and that this feature helps explain human prosocial tendencies. Despite circumstantial evidence that post-reproductive females and extra-pair males both provide resources required for successful reproduction by mated pairs, no study has yet provided details about the flow of food resources by different age and sex categories to breeders and offspring, nor documented the ratio of helpers to breeders. Here, we show in two hunter–gatherer societies of South America that each breeding pair with dependent offspring on average obtained help from approximately 1.3 non-reproductive adults. Young married males and unmarried males of all ages were the main food providers, accounting for 93–100% of all excess food production available to breeding pairs and their offspring. Thus, each breeding pair with dependants was provisioned on average by 0.8 adult male helpers. The data provide no support for the hypothesis that post-reproductive females are the main provisioners of younger reproductive-aged kin in hunter–gatherer societies. Demographic and food acquisition data show that most breeding pairs can expect food deficits owing to foraging luck, health disabilities and accumulating dependency ratio of offspring in middle age, and that extra-pair provisioning may be essential to the evolved human life history. PMID:19692401

  15. Natural selection promotes antigenic evolvability.

    PubMed

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  16. Spacetimes containing slowly evolving horizons

    SciTech Connect

    Kavanagh, William; Booth, Ivan

    2006-08-15

    Slowly evolving horizons are trapping horizons that are ''almost'' isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the mass scales and orders of magnitude that arise in these calculations, we conjecture that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes.

  17. Comparison of 2 Rat Breeding Schemes Using Conventional Caging

    PubMed Central

    Allen, Kenneth P; Dwinell, Melinda R; Zappa, Allison; Temple, Anne; Thulin, Joseph

    2013-01-01

    Compared with earlier editions, the eighth edition of the Guide for the Care and Use of Laboratory Animals recommends more cage floor space for female rats with litters. As such, conventional rat cages often do not supply the recommended floor space to maintain 2 adult rats and a litter in the same cage. We evaluated 2 breeding schemes using traditional cages that afford 140 in.2 (903 cm2) of floor space: (1) monogamous pairs housed continuously and (2) monogamous pairs cohoused intermittently with removal of the male rat after parturition. The results did not demonstrate a significant difference between breeding schemes in generation time, number of litters per breeding pair, percentage of litters weaned, number of pups born per breeding pair, and number of pups weaned per breeding pair. However, the average weaning weight of pups was significantly higher with scheme 1 compared with scheme 2. Collectively, these results indicate continuous housing of monogamous breeding pairs may be preferable to intermittent housing when conventional cages are used. PMID:23562096

  18. Robustness to Faults Promotes Evolvability: Insights from Evolving Digital Circuits

    PubMed Central

    Nolfi, Stefano

    2016-01-01

    We demonstrate how the need to cope with operational faults enables evolving circuits to find more fit solutions. The analysis of the results obtained in different experimental conditions indicates that, in absence of faults, evolution tends to select circuits that are small and have low phenotypic variability and evolvability. The need to face operation faults, instead, drives evolution toward the selection of larger circuits that are truly robust with respect to genetic variations and that have a greater level of phenotypic variability and evolvability. Overall our results indicate that the need to cope with operation faults leads to the selection of circuits that have a greater probability to generate better circuits as a result of genetic variation with respect to a control condition in which circuits are not subjected to faults. PMID:27409589

  19. Robustness to Faults Promotes Evolvability: Insights from Evolving Digital Circuits.

    PubMed

    Milano, Nicola; Nolfi, Stefano

    2016-01-01

    We demonstrate how the need to cope with operational faults enables evolving circuits to find more fit solutions. The analysis of the results obtained in different experimental conditions indicates that, in absence of faults, evolution tends to select circuits that are small and have low phenotypic variability and evolvability. The need to face operation faults, instead, drives evolution toward the selection of larger circuits that are truly robust with respect to genetic variations and that have a greater level of phenotypic variability and evolvability. Overall our results indicate that the need to cope with operation faults leads to the selection of circuits that have a greater probability to generate better circuits as a result of genetic variation with respect to a control condition in which circuits are not subjected to faults.

  20. Breeding without Mendelism: theory and practice of dairy cattle breeding in the Netherlands 1900-1950.

    PubMed

    Theunissen, Bert

    2008-01-01

    In the 1940s and 1950s, Dutch scientists became increasingly critical of the practices of commercial dairy cattle breeders. Milk yields had hardly increased for decades, and the scientists believed this to be due to the fact that breeders still judged the hereditary potential of their animals on the basis of outward characteristics. An objective verdict on the qualities of breeding stock could only be obtained by progeny testing, the scientists contended: the best animals were those that produced the most productive offspring. Some scientists had been making this claim since the beginning of the twentieth century. Why was it that their advice was apparently not heeded by breeders for so long? And what were the methods and beliefs that guided their practices? In this paper I intend to answer these questions by analysing the practical realities of dairy farming and stock breeding in The Netherlands between 1900 and 1950. Breeders continued to employ traditional breeding methods that had proven their effectiveness since the late eighteenth century. Their methods consisted in inbreeding--breeding in 'bloodlines,' as they called it--and selection on the basis of pedigree, conformation and milk recording data. Their aims were 'purity' and 'uniformity' of type. Progeny testing was not practiced due to practical difficulties. Before World War II, scientists acknowledged that genetic theory was of little practical use to breeders of livestock. Still, hereditary theory was considered to be helpful to assess the value of the breeders' methods. For instance, striving for purity was deemed to be consistent with Mendelian theory. Yet the term purity had different connotations for scientists and practical workers. For the former, it referred to homozygosity; for the latter, it rather buttressed the constancy of a distinct commercial 'brand.' Until the 1940s, practical breeders and most scientists were agreed that selecting animals purely for production was ill-advised. Cows of

  1. Mobile computing acceptance grows as applications evolve.

    PubMed

    Porn, Louis M; Patrick, Kelly

    2002-01-01

    Handheld devices are becoming more cost-effective to own, and their use in healthcare environments is increasing. Handheld devices currently are being used for e-prescribing, charge capture, and accessing daily schedules and reference tools. Future applications may include education on medications, dictation, order entry, and test-results reporting. Selecting the right handheld device requires careful analysis of current and future applications, as well as vendor expertise. It is important to recognize the technology will continue to evolve over the next three years.

  2. Time evolving fluid from Vaidya spacetime

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Hao, Xin; Zhao, Liu

    2017-08-01

    A time evolving fluid system is constructed on a timelike boundary hypersurface at finite cutoff in Vaidya spacetime. The approach used to construct the fluid equations is a direct extension of the ordinary gravity/fluid correspondence under the constrained fluctuation obeying Petrov type I conditions. The explicit relationships between the time dependent fluctuation modes and the fluid quantities such as density, velocity field and kinematic viscosity parameters are established, and the resulting fluid system is governed by a system of a sourced continuity equation and a compressible Navier-Stokes equation with nontrivial time evolution.

  3. Genetic distinctiveness of the Herdwick sheep breed and two other locally adapted hill breeds of the UK.

    PubMed

    Bowles, Dianna; Carson, Amanda; Isaac, Peter

    2014-01-01

    There is considerable interest in locally adapted breeds of livestock as reservoirs of genetic diversity that may provide important fitness traits for future use in agriculture. In marginal areas, these animals contribute to food security and extract value from land unsuitable for other systems of farming. In England, close to 50% of the national sheep flock is farmed on grassland designated as disadvantaged areas for agricultural production. Many of these areas are in the uplands, where some native breeds of sheep continue to be commercially farmed only in highly localised geographical regions to which they are adapted. This study focuses on three of these breeds, selected for their adaptation to near identical environments and their geographical concentration in regions close to one another. Our objective has been to use retrotyping, microsatellites and single nucleotide polymorphisms to explore the origins of the breeds and whether, despite their similar adaptations and proximity, they are genetically distinctive. We find the three breeds each have a surprisingly different pattern of retrovirus insertions into their genomes compared with one another and with other UK breeds. Uniquely, there is a high incidence of the R0 retrotype in the Herdwick population, characteristic of a primitive genome found previously in very few breeds worldwide and none in the UK mainland. The Herdwick and Rough Fells carry two rare retroviral insertion events, common only in Texels, suggesting sheep populations in the northern uplands have a historical association with the original pin-tail sheep of Texel Island. Microsatellite data and analyses of SNPs associated with RXFP2 (horn traits) and PRLR (reproductive performance traits) also distinguished the three breeds. Significantly, an SNP linked to TMEM154, a locus controlling susceptibility to infection by Maedi-Visna, indicated that all three native hill breeds have a lower than average risk of infection to the lentivirus.

  4. Genetic Distinctiveness of the Herdwick Sheep Breed and Two Other Locally Adapted Hill Breeds of the UK

    PubMed Central

    Bowles, Dianna; Carson, Amanda; Isaac, Peter

    2014-01-01

    There is considerable interest in locally adapted breeds of livestock as reservoirs of genetic diversity that may provide important fitness traits for future use in agriculture. In marginal areas, these animals contribute to food security and extract value from land unsuitable for other systems of farming. In England, close to 50% of the national sheep flock is farmed on grassland designated as disadvantaged areas for agricultural production. Many of these areas are in the uplands, where some native breeds of sheep continue to be commercially farmed only in highly localised geographical regions to which they are adapted. This study focuses on three of these breeds, selected for their adaptation to near identical environments and their geographical concentration in regions close to one another. Our objective has been to use retrotyping, microsatellites and single nucleotide polymorphisms to explore the origins of the breeds and whether, despite their similar adaptations and proximity, they are genetically distinctive. We find the three breeds each have a surprisingly different pattern of retrovirus insertions into their genomes compared with one another and with other UK breeds. Uniquely, there is a high incidence of the R0 retrotype in the Herdwick population, characteristic of a primitive genome found previously in very few breeds worldwide and none in the UK mainland. The Herdwick and Rough Fells carry two rare retroviral insertion events, common only in Texels, suggesting sheep populations in the northern uplands have a historical association with the original pin-tail sheep of Texel Island. Microsatellite data and analyses of SNPs associated with RXFP2 (horn traits) and PRLR (reproductive performance traits) also distinguished the three breeds. Significantly, an SNP linked to TMEM154, a locus controlling susceptibility to infection by Maedi-Visna, indicated that all three native hill breeds have a lower than average risk of infection to the lentivirus. PMID

  5. RosBREED: Enabling Marker-Assisted Breeding in Rosaceae

    USDA-ARS?s Scientific Manuscript database

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including ES...

  6. Evolving role of pharmaceutical physicians in the industry: Indian perspective.

    PubMed

    Patil, Anant; Rajadhyaksha, Viraj

    2012-01-01

    The Indian pharmaceutical industry, like any other industry, has undergone significant change in the last decade. The role of a Medical advisor has always been of paramount importance in the pharmaceutical companies in India. On account of the evolving medical science and the competitive environment, the medical advisor's role is also increasingly becoming critical. In India, with changes in regulatory rules, safety surveillance, and concept of medical liaisons, the role of the medical advisor is evolving continuously and is further likely to evolve in the coming years in important areas like health economics, public private partnerships, and strategic planning.

  7. Evolving role of pharmaceutical physicians in the industry: Indian perspective

    PubMed Central

    Patil, Anant; Rajadhyaksha, Viraj

    2012-01-01

    The Indian pharmaceutical industry, like any other industry, has undergone significant change in the last decade. The role of a Medical advisor has always been of paramount importance in the pharmaceutical companies in India. On account of the evolving medical science and the competitive environment, the medical advisor's role is also increasingly becoming critical. In India, with changes in regulatory rules, safety surveillance, and concept of medical liaisons, the role of the medical advisor is evolving continuously and is further likely to evolve in the coming years in important areas like health economics, public private partnerships, and strategic planning. PMID:22347701

  8. Animal breeding and disease

    PubMed Central

    Nicholas, Frank W

    2005-01-01

    Single-locus disorders in domesticated animals were among the first Mendelian traits to be documented after the rediscovery of Mendelism, and to be included in early linkage maps. The use of linkage maps and (increasingly) comparative genomics has been central to the identification of the causative gene for single-locus disorders of considerable practical importance. The ‘score-card’ in domestic animals is now more than 100 disorders for which the molecular lesion has been identified and hence for which a DNA test is available. Because of the limited lifespan of any such test, a cost-effective and hence popular means of protecting the intellectual property inherent in a DNA test is not to publish the discovery. While understandable, this practice creates a disconcerting precedent. For multifactorial disorders that are scored on an all-or-none basis or into many classes, the effectiveness of control schemes could be greatly enhanced by selection on estimated breeding values for liability. Genetic variation for resistance to pathogens and parasites is ubiquitous. Selection for resistance can therefore be successful. Because of the technical and welfare challenges inherent in the requirement to expose animals to pathogens or parasites in order to be able to select for resistance, there is a very active search for DNA markers for resistance. The first practical fruits of this research were seen in 2002, with the launch of a national scrapie control programme in the UK. PMID:16048793

  9. [Exaggerated breed characteristics in dogs].

    PubMed

    Wilting, M M; Endenburg, N

    2012-01-01

    Dutch dog owners seem to be aware of bad dog breeding practices with regard to exaggerated breed characteristics that are detrimental to the dog's welfare. Yet they do not always look for these features when buying a dog. Most dog owners think that veterinarians could have an important role in preventing these exaggerated physical traits, by providing information about these traits and taking action in their capacity as veterinarian. Articles 36 and 55 of the Dutch GWWD (animal health and welfare law) provide opportunities to act against the breeding of dogs with exaggerated genetic traits.

  10. Mutation breeding by ion implantation

    NASA Astrophysics Data System (ADS)

    Yu, Zengliang; Deng, Jianguo; He, Jianjun; Huo, Yuping; Wu, Yuejin; Wang, Xuedong; Lui, Guifu

    1991-07-01

    Ion implantation as a new mutagenic method has been used in the rice breeding program since 1986, and for mutation breeding of other crops later. It has been shown, in principle and in practice, that this method has many outstanding advantages: lower damage rate; higher mutation rate and wider mutational spectrum. Many new lines of rice with higher yield rate; broader disease resistance; shorter growing period but higher quality have been bred from ion beam induced mutants. Some of these lines have been utilized for the intersubspecies hybridization. Several new lines of cotton, wheat and other crops are now in breeding. Some biophysical effects of ion implantation for crop seeds have been studied.

  11. [Rice breeding by space technology].

    PubMed

    Li, Yuan-xiang; Li, Jin-guo; Liu, Han-dong; Jiang, Xing-cun; Hua, Yu-jian; Zhou, Huo-liang; Che, Xin-ming

    2002-07-01

    In order to inquire into the influences of space conditions on rice breeding,the dry seeds of 12 rice varieties were carried by recoverable satellite. After recovery,these seeds were showed in the yield, the inheritance and variation of the characters of their progenies were observed and analysed. The results showed that the characters of the progenies mutated under space conditions segregated and varied in many aspects and directions,and the segregated and varied characters were heritable. These progenies posoessed significant transgressive inheritance, a plenty of variation types and variation was characterized by short breeding period. The results in this study indicated that space technology breeding could be developed and used as a new method of mutation breeding.

  12. Breeding gravitational lenses

    NASA Astrophysics Data System (ADS)

    Liesenborgs, J.; de Rijcke, S.; Dejonghe, H.; Bekaert, P.

    2011-03-01

    Gravitational lenses are a spectacular astrophysical phenomenon, a cosmic mirage caused by the gravitational deflection of light in which multiple images of a same background object can be seen. Their beauty is only exceeded by their usefulness, as the gravitational lens effect is a direct probe of the total mass of the deflecting object. Furthermore, since the image configuration arising from the gravitational lens effect depends on the exact gravitational potential of the deflector, it even holds the promise of learning about the distribution of the mass. In this presentation, a method for extracting the information encoded in the images and reconstructing the mass distribution is presented. Being a non-parametric method, it avoids making a priori assumptions about the shape of the mass distribution. At the core of the procedure lies a genetic algorithm, an optimization strategy inspired by Darwin's principle of ``survival of the fittest''. One only needs to specify a criterion to decide if one particular trial solution is deemed better than another, and the genetic algorithm will ``breed'' appropriate solutions to the problem. In a similar way, one can create a multi-objective genetic algorithm, capable of optimizing several fitness criteria at the same time. This provides a very flexible way to incorporate all the available information in the gravitational lens system: not only the positions and shapes of the multiple images are used, but also the so-called ``null space'', i.e. the area in which no such images can be seen. The effectiveness of this approach is illustrated using simulated data, which allows one to compare the reconstruction to the true mass distribution.

  13. Efficient Breeding by Genomic Mating.

    PubMed

    Akdemir, Deniz; Sánchez, Julio I

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

  14. Efficient Breeding by Genomic Mating

    PubMed Central

    Akdemir, Deniz; Sánchez, Julio I.

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population. PMID:27965707

  15. Hybrid breeding in autogamous cereals.

    PubMed

    Longin, Carl Friedrich Horst; Mühleisen, Jonathan; Maurer, Hans Peter; Zhang, Hongliang; Gowda, Manje; Reif, Jochen Christoph

    2012-10-01

    Hybrid breeding in autogamous cereals has a long history of attempts with moderate success. There is a vast amount of literature investigating the potential problems and solutions, but until now, market share of hybrids is still a niche compared to line varieties. Our aim was to summarize the status quo of hybrid breeding efforts for the autogamous cereals wheat, rice, barley, and triticale. Furthermore, the research needs for a successful hybrid breeding in autogamous cereals are intensively discussed. To our opinion, the basic requirements for a successful hybrid breeding in autogamous cereals are fulfilled. Nevertheless, optimization of the existing hybridization systems is urgently required and should be coupled with the development of clear male and female pool concepts. We present a quantitative genetic framework as a first step to compare selection gain of hybrid versus line breeding. The lack of precise empirical estimates of relevant quantitative genetic parameters, however, is currently the major bottleneck for a robust evaluation of the potential of hybrid breeding in autogamous cereals.

  16. The evolving role of the transfusion practitioner.

    PubMed

    Miller, Kristy; Akers, Christine; Davis, Amanda K; Wood, Erica; Hennessy, Clare; Bielby, Linley

    2015-04-01

    Much of the recent work in transfusion practice has shifted to focus on the patient, after efforts over previous decades to ensure the quality and safety of blood products. After the commencement of hemovigilance and transfusion practice improvement programs, the introduction of transfusion practitioners (TP) into health care services and blood centers has continued to increase worldwide. Since this relatively new role was introduced, much work of the TP has focused on patient and staff education, adverse events, transfusion governance, and monitoring of transfusion practices within organizations. The complex nature of the transfusion process makes the TP an integral link in the transfusion chain. Together with hospital transfusion teams and committees, the TP works collaboratively to facilitate the transfusion change management programs and initiatives. Recently, the TP role has evolved to include an emphasis on patient blood management and, to some extent, is shaped by national standards and regulations. These established roles of the TP, together with the ever-changing field of transfusion medicine, provide new opportunities and challenges for a role that is continuing to evolve worldwide. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Evolving Sensitivity Balances Boolean Networks

    PubMed Central

    Luo, Jamie X.; Turner, Matthew S.

    2012-01-01

    We investigate the sensitivity of Boolean Networks (BNs) to mutations. We are interested in Boolean Networks as a model of Gene Regulatory Networks (GRNs). We adopt Ribeiro and Kauffman’s Ergodic Set and use it to study the long term dynamics of a BN. We define the sensitivity of a BN to be the mean change in its Ergodic Set structure under all possible loss of interaction mutations. Insilico experiments were used to selectively evolve BNs for sensitivity to losing interactions. We find that maximum sensitivity was often achievable and resulted in the BNs becoming topologically balanced, i.e. they evolve towards network structures in which they have a similar number of inhibitory and excitatory interactions. In terms of the dynamics, the dominant sensitivity strategy that evolved was to build BNs with Ergodic Sets dominated by a single long limit cycle which is easily destabilised by mutations. We discuss the relevance of our findings in the context of Stem Cell Differentiation and propose a relationship between pluripotent stem cells and our evolved sensitive networks. PMID:22586459

  18. How evolvable are polarization machines?

    NASA Astrophysics Data System (ADS)

    Laan, Liedewij; Murray, Andrew

    2012-02-01

    In many different cell types proper polarization is essential for cell function. Polarization mechanisms however, differ between cell types and even closely related species use a variety of polarization machines. Budding yeast, for example, depends on several parallel mechanisms to establish polarity. One mechanism (i) depends on reaction and diffusion of proteins in the membrane. Another one (ii) depends on reorganization of the actin cytoskeleton. So why does yeast use several mechanisms simultaneously? Can yeast also polarize robustly in the absence of one of them? We addressed these questions by evolving budding yeast in the absence of mechanism (i) or (ii). We deleted a mechanism by deleting one or two genes that are essential for its function. After the deletion of either mechanism the growth rate of cells was highly decreased (2-5 fold) and their cell shape was highly perturbed. Subsequently, we evolved these cells for 10 days. Surprisingly, the evolved cells rapidly overcame most of their polarity defects. They grow at 0.9x wildtype growth rate and their cell shape is signifigantly less perturbed. Now we will study how these cells rescued polarization. Did they fix the deleted mechanism, strengthen other mechanisms or evolve a completely new one?

  19. Slippery Texts and Evolving Literacies

    ERIC Educational Resources Information Center

    Mackey, Margaret

    2007-01-01

    The idea of "slippery texts" provides a useful descriptor for materials that mutate and evolve across different media. Eight adult gamers, encountering the slippery text "American McGee's Alice," demonstrate a variety of ways in which players attempt to manage their attention as they encounter a new text with many resonances. The range of their…

  20. Thermal and evolved gas analyzer

    NASA Technical Reports Server (NTRS)

    Williams, M. S.; Boynton, W. V.; James, R. L.; Verts, W. T.; Bailey, S. H.; Hamara, D. K.

    1998-01-01

    The Thermal and Evolved Gas Analyzer (TEGA) instrument will perform calorimetry and evolved gas analysis on soil samples collected from the Martian surface. TEGA is one of three instruments, along with a robotic arm, that form the Mars Volatile and Climate Survey (MVACS) payload. The other instruments are a stereo surface imager, built by Peter Smith of the University of Arizona and a meteorological station, built by JPL. The MVACS lander will investigate a Martian landing site at approximately 70 deg south latitude. Launch will take place from Kennedy Space Center in January, 1999. The TEGA project started in February, 1996. In the intervening 24 months, a flight instrument concept has been designed, prototyped, built as an engineering model and flight model, and tested. The instrument performs laboratory-quality differential-scanning calorimetry (DSC) over the temperature range of Mars ambient to 1400K. Low-temperature volatiles (water and carbon dioxide ices) and the carbonates will be analyzed in this temperature range. Carbonates melt and evolve carbon dioxide at temperatures above 600 C. Evolved oxygen (down to a concentration of 1 ppm) is detected, and C02 and water vapor and the isotopic variations of C02 and water vapor are detected and their concentrations measured. The isotopic composition provides important tests of the theory of solar system formation.

  1. The Evolving Demand for Skills.

    ERIC Educational Resources Information Center

    Greenspan, Alan

    From a macroeconomic perspective, the evolving demand for skills in the United States has been triggered by the accelerated expansion of computer and information technology, which has, in turn, brought significant changes to the workplace. Technological advances have made some wholly manual jobs obsolete. But even for many other workers, a rapidly…

  2. Signing Apes and Evolving Linguistics.

    ERIC Educational Resources Information Center

    Stokoe, William C.

    Linguistics retains from its antecedents, philology and the study of sacred writings, some of their apologetic and theological bias. Thus it has not been able to face squarely the question how linguistic function may have evolved from animal communication. Chimpanzees' use of signs from American Sign Language forces re-examination of language…

  3. Lettuce and spinach breeding

    USDA-ARS?s Scientific Manuscript database

    Lettuce and spinach production is beset by numerous biotic an abiotic challenges, thus the leafy-vegetable industry of California requires continued development of improved, adapted cultivars to meet new disease and insect problems, changes in the market, and changes in growing procedures. The lettu...

  4. [Prospects of molecular breeding in medical plants].

    PubMed

    Ma, Xiao-Jun; Mo, Chang-Ming

    2017-06-01

    The molecular-assisted breeding, transgenic breeding and molecular designing breeding are three development directions of plant molecular breeding. Base on these three development directions, this paper summarizes developing status and new tendency of research field of genetic linkage mapping, QTL mapping, association mapping, molecular-assisted selections, pollen-mediated transformations, agrobacterium-mediated transformations, particle gun-mediated transformations, genome editing technologies, whole-genome sequencing, transcriptome sequencing, proteome sequencing and varietal molecular designing. The objective and existing problem of medical plant molecular breeding were discussed the prospect of these three molecular breeding technologies application on medical plant molecular breeding was outlooked. Copyright© by the Chinese Pharmaceutical Association.

  5. Breeding and quantitative genetics advances in sunflower Sclerotinia research

    USDA-ARS?s Scientific Manuscript database

    In 2010, we continued the process of backcrossing the head rot QTL from the HA 441 x RHA 439 population into confectionery and elite oilseed backgrounds. Progress is slow due to complexities in scoring of alleles in breeding progenies (dominant markers sometimes in repulsion phase, and many gel band...

  6. Non-uniform Evolving Hypergraphs and Weighted Evolving Hypergraphs

    PubMed Central

    Guo, Jin-Li; Zhu, Xin-Yun; Suo, Qi; Forrest, Jeffrey

    2016-01-01

    Firstly, this paper proposes a non-uniform evolving hypergraph model with nonlinear preferential attachment and an attractiveness. This model allows nodes to arrive in batches according to a Poisson process and to form hyperedges with existing batches of nodes. Both the number of arriving nodes and that of chosen existing nodes are random variables so that the size of each hyperedge is non-uniform. This paper establishes the characteristic equation of hyperdegrees, calculates changes in the hyperdegree of each node, and obtains the stationary average hyperdegree distribution of the model by employing the Poisson process theory and the characteristic equation. Secondly, this paper constructs a model for weighted evolving hypergraphs that couples the establishment of new hyperedges, nodes and the dynamical evolution of the weights. Furthermore, what is obtained are respectively the stationary average hyperdegree and hyperstrength distributions by using the hyperdegree distribution of the established unweighted model above so that the weighted evolving hypergraph exhibits a scale-free behavior for both hyperdegree and hyperstrength distributions. PMID:27845334

  7. Eradication of scrapie with selective breeding: are we nearly there?

    PubMed Central

    2010-01-01

    breeding can decrease as a result of this. This, together with the patterns of direct and indirect contact between sheep farms, might present a challenge of the aim of scrapie eradication. Communication to sheep owners of the effect of the breeding programme thus far, and of the prospects for classical scrapie eradication in The Netherlands might be essential for obtaining useful levels of participation to the voluntary continuation of the breeding programme. PMID:20441587

  8. Haplotype diversity of the myostatin gene among beef cattle breeds

    PubMed Central

    Dunner, Susana; Miranda, M Eugenia; Amigues, Yves; Cañón, Javier; Georges, Michel; Hanset, Roger; Williams, John; Ménissier, François

    2003-01-01

    A total of 678 individuals from 28 European bovine breeds were both phenotyped and analysed at the myostatin locus by the Single Strand Conformation Polymorphism (SSCP) method. Seven new mutations were identified which contribute to the high polymorphism (1 SNP every 100 bp) present in this small gene; twenty haplotypes were described and a genotyping method was set up using the Oligonucleotide Ligation Assay (OLA) method. Some haplotypes appeared to be exclusive to a particular breed; this was the case for 5 in the Charolaise (involving mutation Q204X) and 7 in the Maine-Anjou (involving mutation E226X). The relationships between the different haplotypes were studied, thus allowing to test the earlier hypothesis on the origin of muscular hypertrophy in Europe: muscular hypertrophy (namely nt821(del11)) was mainly spread in different waves from northern Europe milk purpose populations in most breeds; however, other mutations (mostly disruptive) arose in a single breed, were highly selected and have since scarcely evolved to other populations. PMID:12605853

  9. Harnessing Diversity in Wheat to Enhance Grain Yield, Climate Resilience, Disease and Insect Pest Resistance and Nutrition Through Conventional and Modern Breeding Approaches

    PubMed Central

    Mondal, Suchismita; Rutkoski, Jessica E.; Velu, Govindan; Singh, Pawan K.; Crespo-Herrera, Leonardo A.; Guzmán, Carlos; Bhavani, Sridhar; Lan, Caixia; He, Xinyao; Singh, Ravi P.

    2016-01-01

    Current trends in population growth and consumption patterns continue to increase the demand for wheat, a key cereal for global food security. Further, multiple abiotic challenges due to climate change and evolving pathogen and pests pose a major concern for increasing wheat production globally. Triticeae species comprising of primary, secondary, and tertiary gene pools represent a rich source of genetic diversity in wheat. The conventional breeding strategies of direct hybridization, backcrossing and selection have successfully introgressed a number of desirable traits associated with grain yield, adaptation to abiotic stresses, disease resistance, and bio-fortification of wheat varieties. However, it is time consuming to incorporate genes conferring tolerance/resistance to multiple stresses in a single wheat variety by conventional approaches due to limitations in screening methods and the lower probabilities of combining desirable alleles. Efforts on developing innovative breeding strategies, novel tools and utilizing genetic diversity for new genes/alleles are essential to improve productivity, reduce vulnerability to diseases and pests and enhance nutritional quality. New technologies of high-throughput phenotyping, genome sequencing and genomic selection are promising approaches to maximize progeny screening and selection to accelerate the genetic gains in breeding more productive varieties. Use of cisgenic techniques to transfer beneficial alleles and their combinations within related species also offer great promise especially to achieve durable rust resistance. PMID:27458472

  10. Harnessing Diversity in Wheat to Enhance Grain Yield, Climate Resilience, Disease and Insect Pest Resistance and Nutrition Through Conventional and Modern Breeding Approaches.

    PubMed

    Mondal, Suchismita; Rutkoski, Jessica E; Velu, Govindan; Singh, Pawan K; Crespo-Herrera, Leonardo A; Guzmán, Carlos; Bhavani, Sridhar; Lan, Caixia; He, Xinyao; Singh, Ravi P

    2016-01-01

    Current trends in population growth and consumption patterns continue to increase the demand for wheat, a key cereal for global food security. Further, multiple abiotic challenges due to climate change and evolving pathogen and pests pose a major concern for increasing wheat production globally. Triticeae species comprising of primary, secondary, and tertiary gene pools represent a rich source of genetic diversity in wheat. The conventional breeding strategies of direct hybridization, backcrossing and selection have successfully introgressed a number of desirable traits associated with grain yield, adaptation to abiotic stresses, disease resistance, and bio-fortification of wheat varieties. However, it is time consuming to incorporate genes conferring tolerance/resistance to multiple stresses in a single wheat variety by conventional approaches due to limitations in screening methods and the lower probabilities of combining desirable alleles. Efforts on developing innovative breeding strategies, novel tools and utilizing genetic diversity for new genes/alleles are essential to improve productivity, reduce vulnerability to diseases and pests and enhance nutritional quality. New technologies of high-throughput phenotyping, genome sequencing and genomic selection are promising approaches to maximize progeny screening and selection to accelerate the genetic gains in breeding more productive varieties. Use of cisgenic techniques to transfer beneficial alleles and their combinations within related species also offer great promise especially to achieve durable rust resistance.

  11. Coupled oscillators on evolving networks

    NASA Astrophysics Data System (ADS)

    Singh, R. K.; Bagarti, Trilochan

    2016-12-01

    In this work we study coupled oscillators on evolving networks. We find that the steady state behavior of the system is governed by the relative values of the spread in natural frequencies and the global coupling strength. For coupling strong in comparison to the spread in frequencies, the system of oscillators synchronize and when coupling strength and spread in frequencies are large, a phenomenon similar to amplitude death is observed. The network evolution provides a mechanism to build inter-oscillator connections and once a dynamic equilibrium is achieved, oscillators evolve according to their local interactions. We also find that the steady state properties change by the presence of additional time scales. We demonstrate these results based on numerical calculations studying dynamical evolution of limit-cycle and van der Pol oscillators.

  12. Exploring natural selection to guide breeding for agriculture.

    PubMed

    Henry, Robert James; Nevo, Eviatar

    2014-08-01

    Climate change threatens reduced crop production and poses major challenges to food security. The breeding of climate-resilient crop varieties is increasingly urgent. Wild plant populations evolve to cope with changes in their environment due to the forces of natural selection. This adaptation may be followed over time in populations at the same site or explored by examining differences between populations growing in different environments or across an environmental gradient. Survival in the wild has important differences to the objective of agriculture to maximize crop yields. However, understanding the nature of adaptation in wild populations at the whole genome level may suggest strategies for crop breeding to deliver agricultural production with more resilience to climate variability. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  13. Evolvable Hardware for Space Applications

    NASA Technical Reports Server (NTRS)

    Lohn, Jason; Globus, Al; Hornby, Gregory; Larchev, Gregory; Kraus, William

    2004-01-01

    This article surveys the research of the Evolvable Systems Group at NASA Ames Research Center. Over the past few years, our group has developed the ability to use evolutionary algorithms in a variety of NASA applications ranging from spacecraft antenna design, fault tolerance for programmable logic chips, atomic force field parameter fitting, analog circuit design, and earth observing satellite scheduling. In some of these applications, evolutionary algorithms match or improve on human performance.

  14. Cassava Breeding I: The Value of Breeding Value

    PubMed Central

    Ceballos, Hernán; Pérez, Juan C.; Joaqui Barandica, Orlando; Lenis, Jorge I.; Morante, Nelson; Calle, Fernando; Pino, Lizbeth; Hershey, Clair H.

    2016-01-01

    Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials—UYT). This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN) used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g., high number of their progenies reaching the UYT), suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r2 = 0.05). Breeding value (e.g., average SIN) at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g., S1 or S2 genotypes) would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0) parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease (CMD) could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele and

  15. Ranking in evolving complex networks

    NASA Astrophysics Data System (ADS)

    Liao, Hao; Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng; Zhou, Ming-Yang

    2017-05-01

    Complex networks have emerged as a simple yet powerful framework to represent and analyze a wide range of complex systems. The problem of ranking the nodes and the edges in complex networks is critical for a broad range of real-world problems because it affects how we access online information and products, how success and talent are evaluated in human activities, and how scarce resources are allocated by companies and policymakers, among others. This calls for a deep understanding of how existing ranking algorithms perform, and which are their possible biases that may impair their effectiveness. Many popular ranking algorithms (such as Google's PageRank) are static in nature and, as a consequence, they exhibit important shortcomings when applied to real networks that rapidly evolve in time. At the same time, recent advances in the understanding and modeling of evolving networks have enabled the development of a wide and diverse range of ranking algorithms that take the temporal dimension into account. The aim of this review is to survey the existing ranking algorithms, both static and time-aware, and their applications to evolving networks. We emphasize both the impact of network evolution on well-established static algorithms and the benefits from including the temporal dimension for tasks such as prediction of network traffic, prediction of future links, and identification of significant nodes.

  16. Evolving Systems and Adaptive Key Component Control

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Balas, Mark J.

    2009-01-01

    We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. An introduction to Evolving Systems and exploration of the essential topics of the control and stability properties of Evolving Systems is provided. This chapter defines a framework for Evolving Systems, develops theory and control solutions for fundamental characteristics of Evolving Systems, and provides illustrative examples of Evolving Systems and their control with adaptive key component controllers.

  17. Emperor penguins breeding on iceshelves.

    PubMed

    Fretwell, Peter T; Trathan, Phil N; Wienecke, Barbara; Kooyman, Gerald L

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

  18. Netgram: Visualizing Communities in Evolving Networks

    PubMed Central

    Mall, Raghvendra; Langone, Rocco; Suykens, Johan A. K.

    2015-01-01

    Real-world complex networks are dynamic in nature and change over time. The change is usually observed in the interactions within the network over time. Complex networks exhibit community like structures. A key feature of the dynamics of complex networks is the evolution of communities over time. Several methods have been proposed to detect and track the evolution of these groups over time. However, there is no generic tool which visualizes all the aspects of group evolution in dynamic networks including birth, death, splitting, merging, expansion, shrinkage and continuation of groups. In this paper, we propose Netgram: a tool for visualizing evolution of communities in time-evolving graphs. Netgram maintains evolution of communities over 2 consecutive time-stamps in tables which are used to create a query database using the sql outer-join operation. It uses a line-based visualization technique which adheres to certain design principles and aesthetic guidelines. Netgram uses a greedy solution to order the initial community information provided by the evolutionary clustering technique such that we have fewer line cross-overs in the visualization. This makes it easier to track the progress of individual communities in time evolving graphs. Netgram is a generic toolkit which can be used with any evolutionary community detection algorithm as illustrated in our experiments. We use Netgram for visualization of topic evolution in the NIPS conference over a period of 11 years and observe the emergence and merging of several disciplines in the field of information processing systems. PMID:26356538

  19. Breeding monkeys for biomedical research

    NASA Technical Reports Server (NTRS)

    Bourne, G. H.; Golarzdebourne, M. N.; Keeling, M. E.

    1973-01-01

    Captive bred rhesus monkeys show much less pathology than wild born animals. The monkeys may be bred in cages or in an outdoor compound. Cage bred animals are not psychologically normal which makes then unsuited for some types of space related research. Compound breeding provides contact between mother and infant and an opportunity for the infants to play with their peers which are important requirements to help maintain their behavioral integrity. Offspring harvested after a year in the compound appear behaviorally normal and show little histopathology. Compound breeding is also an economical method for the rapid production of young animals. The colony can double its size about every two and a half years.

  20. Breeding monkeys for biomedical research

    NASA Technical Reports Server (NTRS)

    Bourne, G. H.; Golarzdebourne, M. N.; Keeling, M. E.

    1973-01-01

    Captive bred rhesus monkeys show much less pathology than wild born animals. The monkeys may be bred in cages or in an outdoor compound. Cage bred animals are not psychologically normal which makes then unsuited for some types of space related research. Compound breeding provides contact between mother and infant and an opportunity for the infants to play with their peers which are important requirements to help maintain their behavioral integrity. Offspring harvested after a year in the compound appear behaviorally normal and show little histopathology. Compound breeding is also an economical method for the rapid production of young animals. The colony can double its size about every two and a half years.

  1. Breed base representation in dairy animals of 5 breeds

    USDA-ARS?s Scientific Manuscript database

    Inheritance of DNA from different dairy breeds can be determined by genotyping, just as individual ancestors such as parents, grandparents, or even great grandparents can be identified correctly in a high percentage of the cases by genotyping even if not reported or reported incorrectly in pedigrees...

  2. Comparison of molecular breeding values based on within- and across-breed training in beef cattle.

    PubMed

    Kachman, Stephen D; Spangler, Matthew L; Bennett, Gary L; Hanford, Kathryn J; Kuehn, Larry A; Snelling, Warren M; Thallman, R Mark; Saatchi, Mahdi; Garrick, Dorian J; Schnabel, Robert D; Taylor, Jeremy F; Pollak, E John

    2013-08-16

    Although the efficacy of genomic predictors based on within-breed training looks promising, it is necessary to develop and evaluate across-breed predictors for the technology to be fully applied in the beef industry. The efficacies of genomic predictors trained in one breed and utilized to predict genetic merit in differing breeds based on simulation studies have been reported, as have the efficacies of predictors trained using data from multiple breeds to predict the genetic merit of purebreds. However, comparable studies using beef cattle field data have not been reported. Molecular breeding values for weaning and yearling weight were derived and evaluated using a database containing BovineSNP50 genotypes for 7294 animals from 13 breeds in the training set and 2277 animals from seven breeds (Angus, Red Angus, Hereford, Charolais, Gelbvieh, Limousin, and Simmental) in the evaluation set. Six single-breed and four across-breed genomic predictors were trained using pooled data from purebred animals. Molecular breeding values were evaluated using field data, including genotypes for 2227 animals and phenotypic records of animals born in 2008 or later. Accuracies of molecular breeding values were estimated based on the genetic correlation between the molecular breeding value and trait phenotype. With one exception, the estimated genetic correlations of within-breed molecular breeding values with trait phenotype were greater than 0.28 when evaluated in the breed used for training. Most estimated genetic correlations for the across-breed trained molecular breeding values were moderate (> 0.30). When molecular breeding values were evaluated in breeds that were not in the training set, estimated genetic correlations clustered around zero. Even for closely related breeds, within- or across-breed trained molecular breeding values have limited prediction accuracy for breeds that were not in the training set. For breeds in the training set, across- and within-breed trained

  3. Optimists' Creed: Brave New Cyberlearning, Evolving Utopias (Circa 2041)

    ERIC Educational Resources Information Center

    Burleson, Winslow; Lewis, Armanda

    2016-01-01

    This essay imagines the role that artificial intelligence innovations play in the integrated living, learning and research environments of 2041. Here, in 2041, in the context of increasingly complex wicked challenges, whose solutions by their very nature continue to evade even the most capable experts, society and technology have co-evolved to…

  4. Optimists' Creed: Brave New Cyberlearning, Evolving Utopias (Circa 2041)

    ERIC Educational Resources Information Center

    Burleson, Winslow; Lewis, Armanda

    2016-01-01

    This essay imagines the role that artificial intelligence innovations play in the integrated living, learning and research environments of 2041. Here, in 2041, in the context of increasingly complex wicked challenges, whose solutions by their very nature continue to evade even the most capable experts, society and technology have co-evolved to…

  5. Evolving resistance among Gram-positive pathogens.

    PubMed

    Munita, Jose M; Bayer, Arnold S; Arias, Cesar A

    2015-09-15

    Antimicrobial therapy is a key component of modern medical practice and a cornerstone for the development of complex clinical interventions in critically ill patients. Unfortunately, the increasing problem of antimicrobial resistance is now recognized as a major public health threat jeopardizing the care of thousands of patients worldwide. Gram-positive pathogens exhibit an immense genetic repertoire to adapt and develop resistance to virtually all antimicrobials clinically available. As more molecules become available to treat resistant gram-positive infections, resistance emerges as an evolutionary response. Thus, antimicrobial resistance has to be envisaged as an evolving phenomenon that demands constant surveillance and continuous efforts to identify emerging mechanisms of resistance to optimize the use of antibiotics and create strategies to circumvent this problem. Here, we will provide a broad perspective on the clinical aspects of antibiotic resistance in relevant gram-positive pathogens with emphasis on the mechanistic strategies used by these organisms to avoid being killed by commonly used antimicrobial agents.

  6. Life cycle planning: An evolving concept

    SciTech Connect

    Moore, P.J.R.; Gorman, I.G.

    1994-12-31

    Life-cycle planning is an evolving concept in the management of oil and gas projects. BHP Petroleum now interprets this idea to include all development planning from discovery and field appraisal to final abandonment and includes safety, environmental, technical, plant, regulatory, and staffing issues. This article describes in the context of the Timor Sea, how despite initial successes and continuing facilities upgrades, BHPP came to perceive that current operations could be the victim of early development successes, particularly in the areas of corrosion and maintenance. The search for analogies elsewhere lead to the UK North Sea, including the experiences of Britoil and BP, both of which performed detailed Life of Field studies in the later eighties. These materials have been used to construct a format and content for total Life-cycle plans in general and the social changes required to ensure their successful application in Timor Sea operations and deployment throughout Australia.

  7. New nuclear build and evolving radiation protection challenges.

    PubMed

    Lazo, Edward

    2011-01-01

    Radiological protection has continued to evolve in order to meet emerging challenges and will continue to do so. This paper will discuss the scientific and social challenges that will or may be faced by the radiological protection community in the coming 10 to 20 y and how these may affect what is expected to be a renewed interest in building and operating nuclear power plants for electricity generation. Copyright © 2010 Health Physics Society

  8. The evolvability of programmable hardware

    PubMed Central

    Raman, Karthik; Wagner, Andreas

    2011-01-01

    In biological systems, individual phenotypes are typically adopted by multiple genotypes. Examples include protein structure phenotypes, where each structure can be adopted by a myriad individual amino acid sequence genotypes. These genotypes form vast connected ‘neutral networks’ in genotype space. The size of such neutral networks endows biological systems not only with robustness to genetic change, but also with the ability to evolve a vast number of novel phenotypes that occur near any one neutral network. Whether technological systems can be designed to have similar properties is poorly understood. Here we ask this question for a class of programmable electronic circuits that compute digital logic functions. The functional flexibility of such circuits is important in many applications, including applications of evolutionary principles to circuit design. The functions they compute are at the heart of all digital computation. We explore a vast space of 1045 logic circuits (‘genotypes’) and 1019 logic functions (‘phenotypes’). We demonstrate that circuits that compute the same logic function are connected in large neutral networks that span circuit space. Their robustness or fault-tolerance varies very widely. The vicinity of each neutral network contains circuits with a broad range of novel functions. Two circuits computing different functions can usually be converted into one another via few changes in their architecture. These observations show that properties important for the evolvability of biological systems exist in a commercially important class of electronic circuitry. They also point to generic ways to generate fault-tolerant, adaptable and evolvable electronic circuitry. PMID:20534598

  9. Regolith Evolved Gas Analyzer (REGA)

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; McKay, David S.

    1997-01-01

    The instrument consists of five subsystems: (1) a programmable furnace which can be loaded with samples of regolith, (2) a mass spectrometer which detects and measures atmospheric gases or gases evolved during heating, (3) a tank of pressurized gas which can be introduced to the regolith material while detecting and measuring volatile reaction products, (4) a mechanism for dumping the regolith sample and repeating the experiment on a fresh sample, and (5) a data system which controls and monitors the furnace, gas system, and mass spectrometer.

  10. The 'E' factor -- evolving endodontics.

    PubMed

    Hunter, M J

    2013-03-01

    Endodontics is a constantly developing field, with new instruments, preparation techniques and sealants competing with trusted and traditional approaches to tooth restoration. Thus general dental practitioners must question and understand the significance of these developments before adopting new practices. In view of this, the aim of this article, and the associated presentation at the 2013 British Dental Conference & Exhibition, is to provide an overview of endodontic methods and constantly evolving best practice. The presentation will review current preparation techniques, comparing rotary versus reciprocation, and question current trends in restoration of the endodontically treated tooth.

  11. Regolith Evolved Gas Analyzer (REGA)

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; McKay, David S.

    1997-01-01

    The instrument consists of five subsystems: (1) a programmable furnace which can be loaded with samples of regolith, (2) a mass spectrometer which detects and measures atmospheric gases or gases evolved during heating, (3) a tank of pressurized gas which can be introduced to the regolith material while detecting and measuring volatile reaction products, (4) a mechanism for dumping the regolith sample and repeating the experiment on a fresh sample, and (5) a data system which controls and monitors the furnace, gas system, and mass spectrometer.

  12. Improving Evolvability through Generative Representations

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.

    2004-01-01

    One of the main limitations of computer automated design systems is the representation used for encoding designs. Using computer programs as an analogy, representations can be thought of as having the properties of combination, control-flow and abstraction. Generative representations are those which have the ability to reuse elements in an encoding through either iteration, a form of control-flow, or abstraction. Here we argue that generative representations improve the evolvability of designs by capturing design dependencies in a way that makes them easier to change, and we support this with examples from two design substrates.

  13. Languages evolve in punctuational bursts.

    PubMed

    Atkinson, Quentin D; Meade, Andrew; Venditti, Chris; Greenhill, Simon J; Pagel, Mark

    2008-02-01

    Linguists speculate that human languages often evolve in rapid or punctuational bursts, sometimes associated with their emergence from other languages, but this phenomenon has never been demonstrated. We used vocabulary data from three of the world's major language groups-Bantu, Indo-European, and Austronesian-to show that 10 to 33% of the overall vocabulary differences among these languages arose from rapid bursts of change associated with language-splitting events. Our findings identify a general tendency for increased rates of linguistic evolution in fledgling languages, perhaps arising from a linguistic founder effect or a desire to establish a distinct social identity.

  14. Application of genomics to molecular breeding of wheat and barley.

    PubMed

    Varshney, Rajeev K; Langridge, Peter; Graner, Andreas

    2007-01-01

    In wheat and barley, several generations of selectable molecular markers have been included in the genetic maps; and a large number of qualitative and quantitative traits were located in the genomes, some of which are being routinely selected in marker-assisted breeding programs. In recent years, a large number of expressed sequence tags (ESTs) have been generated for wheat and barley that have been used for development of functional molecular markers, preparation of transcript maps, and construction of cDNA arrays. These functional genomic resources combined together with new approaches such as expression genetics, association mapping, allele mining, and informatics (bioinformatic tools) possess potential to identify genes responsible for a trait and their deployment in practical plant breeding. High costs currently limit the implementation of functional genomics in breeding programs. The potential applications together with some examples as well as challenges for applying genomics research in breeding activities are discussed. Genomics research will continue to enhance the efficiency and precision for crop improvement but will not replace conventional breeding and evaluation methods.

  15. Community-based alternative breeding plans for indigenous sheep breeds in four agro-ecological zones of Ethiopia.

    PubMed

    Mirkena, T; Duguma, G; Willam, A; Wurzinger, M; Haile, A; Rischkowsky, B; Okeyo, A M; Tibbo, M; Solkner, J

    2012-06-01

    Based on the results of participatory approaches to define traits in the breeding objectives, four scenarios of ram selection and ram use were compared via deterministic modelling of breeding plans for community-based sheep breeding programmes in four diverse agro-ecological regions of Ethiopia. The regions (and production systems) were Afar (pastoral/agro-pastoral), Bonga and Horro (both mixed crop-livestock) and Menz (sheep-barley). The schemes or scenarios differed in terms of selection intensity and duration of ram use. The predicted genetic gains per year in yearling weight (kilograms) were comparable across the schemes but differed among the breeds and ranged from 0.399 to 0.440 in Afar, 0.813 to 0.894 in Bonga, 0.850 to 0.940 in Horro, and 0.616 to 0.699 in Menz. The genetic gains per year in number of lambs born per ewe bred ranged from 0.009 to 0.010 in both Bonga and Horro. The predicted genetic gain in the proportion of lambs weaned per ewe joined was nearly comparable in all breeds ranging from 0.008 to 0.011. The genetic gain per year in milk yield of Afar breed was in the order of 0.018 to 0.020 kg, while the genetic gain per generation for greasy fleece weight (kg) ranged from 0.016 to 0.024 in Menz. Generally, strong selection and shorter duration of ram use for breeding were the preferred options. The expected genetic gains are satisfactory but largely rely on accurate and continuous pedigree and performance recording. © 2011 Blackwell Verlag GmbH.

  16. Genetic diversity and genomic signatures of selection among cattle breeds from Siberia, eastern and northern Europe.

    PubMed

    Iso-Touru, T; Tapio, M; Vilkki, J; Kiseleva, T; Ammosov, I; Ivanova, Z; Popov, R; Ozerov, M; Kantanen, J

    2016-12-01

    Domestication in the near eastern region had a major impact on the gene pool of humpless taurine cattle (Bos taurus). As a result of subsequent natural and artificial selection, hundreds of different breeds have evolved, displaying a broad range of phenotypic traits. Here, 10 Eurasian B. taurus breeds from different biogeographic and production conditions, which exhibit different demographic histories and have been under artificial selection at various intensities, were investigated using the Illumina BovineSNP50 panel to understand their genetic diversity and population structure. In addition, we scanned genomes from eight breeds for signatures of diversifying selection. Our population structure analysis indicated six distinct breed groups, the most divergent being the Yakutian cattle from Siberia. Selection signals were shared (experimental P-value < 0.01) with more than four breeds on chromosomes 6, 7, 13, 16 and 22. The strongest selection signals in the Yakutian cattle were found on chromosomes 7 and 21, where a miRNA gene and genes related to immune system processes are respectively located. In general, genomic regions indicating selection overlapped with known QTL associated with milk production (e.g. on chromosome 19), reproduction (e.g. on chromosome 24) and meat quality (e.g. on chromosome 7). The selection map created in this study shows that native cattle breeds and their genetic resources represent unique material for future breeding.

  17. Nutrient reserve dynamics of breeding canvasbacks

    USGS Publications Warehouse

    Barzen, J.A.; Serie, J.R.

    1990-01-01

    We compared nutrients in reproductive and nonreproductive tissues of breeding Canvasbacks (Aythya valisineria) to assess the relative importance of endogenous reserves and exogenous foods. Fat reserves of females increased during rapid follicle growth and varied more widely in size during the early phase of this period. Females began laying with ca. 205 g of fat in reserve and lost 1.8 g of carcass fat for every 1 g of fat contained in their ovary and eggs. Females lost body mass (primarily fat) at a declining rate as incubation advanced. Protein reserves increased directly with dry oviduct mass during rapid follicle growth. This direct relationship was highly dependent upon data from 2 birds and likely biased by structural size. During laying, protein reserves did not vary with the combined mass of dry oviduct and dry egg protein. Between laying and incubation, mean protein reserves decreased by an amount equal to the protein found in 2.1 Canvasback eggs. Calcium reserves did not vary with the cumulative total of calcium deposited in eggs. Mean calcium reserve declined by the equivalent content of 1.2 eggs between laying and incubation. We believe that protein and calcium were stored in small amounts during laying, and that they were supplemented continually by exogenous sources. In contrast, fat was stored in large amounts and contributed significantly to egg production and body maintenance. Male Canvasbacks lost fat steadily--but not protein or calcium--as the breeding season progressed.

  18. Nutrient reserve dynamics of breeding canvasbacks

    USGS Publications Warehouse

    Barzen, Jeb A.; Serie, Jerome R.

    1990-01-01

    We compared nutrients in reproductive and nonreproductive tissues of breeding Canvasbacks (Aythya valisineria) to assess the relative importance of endogenous reserves and exogenous foods. Fat reserves of females increased during rapid follicle growth and varied more widely in size during the early phase of this period. Females began laying with ca. 205 g of fat in reserve and lost 1.8 g of carcass fat for every 1 g of fat contained in their ovary and eggs. Females lost body mass (primarily fat) at a declining rate as incubation advanced. Protein reserves increased directly with dry oviduct mass during rapid follicle growth. This direct relationship was highly dependent upon data from 2 birds and likely biased by structural size. During laying, protein reserves did not vary with the combined mass of dry oviduct and dry egg protein. Between laying and incubation, mean protein reserves decreased by an amount equal to the protein found in 2.1 Canvasback eggs. Calcium reserves did not vary with the cumulative total of calcium deposited in eggs. Mean calcium reserve declined by the equivalent content of 1.2 eggs between laying and incubation. We believe that protein and calcium were stored in small amounts during laying, and that they were supplemented continually by exogenous sources. In contrast, fat was stored in large amounts and contributed significantly to egg production and body maintenance. Male Canvasbacks lost fat steadily-but not protein or calcium-as the breeding season progressed.

  19. Chapter 6: Breeding season ecology

    Treesearch

    Mark K. Sogge

    2000-01-01

    The willow flycatcher (Empidonax traillii) breeds across much of the conterminous United States and in portions of extreme southern Canada. As might be expected in such a wide-ranging species, willow flycatchers in different portions of the range exhibit differences in appearance, song, and ecological characteristics. The intent of this chapter is to...

  20. Breeding and propagating oakleaf hydrangeas

    USDA-ARS?s Scientific Manuscript database

    An oakleaf hydrangea breeding program at the U.S. National Arboretum’s worksite in McMinnville, Tenn. was started in 1996 for the purpose of developing attractive, compact oakleaf hydrangea cultivars suitable for use in small residential gardens. ‘Ruby Slippers’ and ‘Munchkin’ oakleaf hydrangeas we...

  1. The evolution of potato breeding

    USDA-ARS?s Scientific Manuscript database

    Potato cultivars in most regions of the world are tetraploid and clonally propagated. For over a century, the breeding strategy has been phenotypic recurrent selection. However, the polyploid nature of the crop prevents breeders from eliminating deleterious alleles and assembling positive alleles fo...

  2. Improving the breeding bird survey

    Treesearch

    Jonathan Bart; Joseph B. Buchanan; Bob Altman

    2005-01-01

    We investigated increasing the number of Breeding Bird Survey (BBS) routes and reducing potential bias as ways to increase the number of species adequately monitored by the BBS in the Pacific Northwest. Estimates of place-to-place variance in trends were used to assess the effects of increasing the number of additional BBS routes. Increasing the number of BBS routes...

  3. Accuracies of genomically estimated breeding values from pure-breed and across-breed predictions in Australian beef cattle.

    PubMed

    Boerner, Vinzent; Johnston, David J; Tier, Bruce

    2014-10-24

    The major obstacles for the implementation of genomic selection in Australian beef cattle are the variety of breeds and in general, small numbers of genotyped and phenotyped individuals per breed. The Australian Beef Cooperative Research Center (Beef CRC) investigated these issues by deriving genomic prediction equations (PE) from a training set of animals that covers a range of breeds and crosses including Angus, Murray Grey, Shorthorn, Hereford, Brahman, Belmont Red, Santa Gertrudis and Tropical Composite. This paper presents accuracies of genomically estimated breeding values (GEBV) that were calculated from these PE in the commercial pure-breed beef cattle seed stock sector. PE derived by the Beef CRC from multi-breed and pure-breed training populations were applied to genotyped Angus, Limousin and Brahman sires and young animals, but with no pure-breed Limousin in the training population. The accuracy of the resulting GEBV was assessed by their genetic correlation to their phenotypic target trait in a bi-variate REML approach that models GEBV as trait observations. Accuracies of most GEBV for Angus and Brahman were between 0.1 and 0.4, with accuracies for abattoir carcass traits generally greater than for live animal body composition traits and reproduction traits. Estimated accuracies greater than 0.5 were only observed for Brahman abattoir carcass traits and for Angus carcass rib fat. Averaged across traits within breeds, accuracies of GEBV were highest when PE from the pooled across-breed training population were used. However, for the Angus and Brahman breeds the difference in accuracy from using pure-breed PE was small. For the Limousin breed no reasonable results could be achieved for any trait. Although accuracies were generally low compared to published accuracies estimated within breeds, they are in line with those derived in other multi-breed populations. Thus PE developed by the Beef CRC can contribute to the implementation of genomic selection in

  4. Transport on randomly evolving trees

    NASA Astrophysics Data System (ADS)

    Pál, L.

    2005-11-01

    The time process of transport on randomly evolving trees is investigated. By introducing the notions of living and dead nodes, a model of random tree evolution is constructed which describes the spreading in time of objects corresponding to nodes. It is assumed that at t=0 the tree consists of a single living node (root), from which the evolution may begin. At a certain time instant τ⩾0 , the root produces ν⩾0 living nodes connected by lines to the root which becomes dead at the moment of the offspring production. In the evolution process each of the new living nodes evolves further like a root independently of the others. By using the methods of the age-dependent branching processes we derive the joint distribution function of the numbers of living and dead nodes, and determine the correlation between these node numbers as a function of time. It is proved that the correlation function converges to 3/2 independently of the distributions of ν and τ when q1→1 and t→∞ . Also analyzed are the stochastic properties of the end nodes; and the correlation between the numbers of living and dead end nodes is shown to change its character suddenly at the very beginning of the evolution process. The survival probability of random trees is investigated and expressions are derived for this probability.

  5. Transport on randomly evolving trees.

    PubMed

    Pál, L

    2005-11-01

    The time process of transport on randomly evolving trees is investigated. By introducing the notions of living and dead nodes, a model of random tree evolution is constructed which describes the spreading in time of objects corresponding to nodes. It is assumed that at t=0 the tree consists of a single living node (root), from which the evolution may begin. At a certain time instant tau> or =0, the root produces v> or =0 living nodes connected by lines to the root which becomes dead at the moment of the offspring production. In the evolution process each of the new living nodes evolves further like a root independently of the others. By using the methods of the age-dependent branching processes we derive the joint distribution function of the numbers of living and dead nodes, and determine the correlation between these node numbers as a function of time. It is proved that the correlation function converges to square root of 3/2 independently of the distributions of v and tau when q1-->1 and t-->infinity. Also analyzed are the stochastic properties of the end nodes; and the correlation between the numbers of living and dead end nodes is shown to change its character suddenly at the very beginning of the evolution process. The survival probability of random trees is investigated and expressions are derived for this probability.

  6. Stability of Evolving Multiagent Systems.

    PubMed

    De Wilde, P; Briscoe, G

    2011-08-01

    A multiagent system is a distributed system where the agents or nodes perform complex functions that cannot be written down in analytic form. Multiagent systems are highly connected, and the information they contain is mostly stored in the connections. When agents update their state, they take into account the state of the other agents, and they have access to those states via the connections. There is also external user-generated input into the multiagent system. As so much information is stored in the connections, agents are often memory less. This memory-less property, together with the randomness of the external input, has allowed us to model multiagent systems using Markov chains. In this paper, we look at multiagent systems that evolve, i.e., the number of agents varies according to the fitness of the individual agents. We extend our Markov chain model and define stability. This is the start of a methodology to control multiagent systems. We then build upon this to construct an entropy-based definition for the degree of instability (entropy of the limit probabilities), which we used to perform a stability analysis. We then investigated the stability of evolving agent populations through simulation and show that the results are consistent with the original definition of stability in nonevolving multiagent systems, proposed by Chli and De Wilde. This paper forms the theoretical basis for the construction of digital business ecosystems, and applications have been reported elsewhere.

  7. Evolving Robust Gene Regulatory Networks

    PubMed Central

    Noman, Nasimul; Monjo, Taku; Moscato, Pablo; Iba, Hitoshi

    2015-01-01

    Design and implementation of robust network modules is essential for construction of complex biological systems through hierarchical assembly of ‘parts’ and ‘devices’. The robustness of gene regulatory networks (GRNs) is ascribed chiefly to the underlying topology. The automatic designing capability of GRN topology that can exhibit robust behavior can dramatically change the current practice in synthetic biology. A recent study shows that Darwinian evolution can gradually develop higher topological robustness. Subsequently, this work presents an evolutionary algorithm that simulates natural evolution in silico, for identifying network topologies that are robust to perturbations. We present a Monte Carlo based method for quantifying topological robustness and designed a fitness approximation approach for efficient calculation of topological robustness which is computationally very intensive. The proposed framework was verified using two classic GRN behaviors: oscillation and bistability, although the framework is generalized for evolving other types of responses. The algorithm identified robust GRN architectures which were verified using different analysis and comparison. Analysis of the results also shed light on the relationship among robustness, cooperativity and complexity. This study also shows that nature has already evolved very robust architectures for its crucial systems; hence simulation of this natural process can be very valuable for designing robust biological systems. PMID:25616055

  8. Conservation priorities for Ethiopian sheep breeds combining threat status, breed merits and contributions to genetic diversity

    PubMed Central

    Gizaw, Solomon; Komen, Hans; Windig, Jack J; Hanotte, Olivier; van Arendonk, Johan AM

    2008-01-01

    Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits) and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding's marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers) and current merits (economic, ecological and cultural merits). Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04) as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83). We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan. PMID:18558075

  9. Mass Loss and Dust Injection rates from Evolved Stars

    NASA Astrophysics Data System (ADS)

    Sargent, Benjamin A.

    2010-01-01

    The Spitzer Space Telescope is continuing to contribute greatly to our understanding of the mass return from evolved stars in the Magellanic Clouds (MCs). I first review a number of smaller early Spitzer studies of evolved stars in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC). These studies often built upon earlier such studies using data from prior missions, like the Midcourse Space Experiment. I discuss various Spitzer spectroscopic studies that have investigated the dust compositions of evolved stars in the lower metallicity environments of the MCs. Also, I review studies of the MCs' massive evolved stars, which have been given somewhat less attention than other populations. Excitingly, using Spitzer data, for the first time the mass-loss from the diverse evolved star MC populations is being quantified. With the advent of the Surveying the Agents of a Galaxy's Evolution (SAGE; PI: M. Meixner) Spitzer Legacy program, tens of thousands of stars in the LMC have been classified as evolved stars using SAGE Spitzer data. I briefly review how evolved stars are classified (e.g., by using color-magnitude and color-color diagrams) using data from the SAGE surveys. Finally, I discuss work on radiative transfer (RT) modeling of evolved stars, which follows earlier work estimating their mass-loss using colors or emission in excess of stellar photosphere emission. This RT work starts by seeking acceptable dust properties for RT models of both SAGE Spectral Energy Distributions (SEDs) and SAGE-Spectroscopy (Spitzer Legacy program; PI: F. Kemper) spectra of asymptotic giant branch (AGB) stars. Afterwards, large grids of RT models are constructed to determine mass-loss rates for AGB stars and red supergiants in the SAGE samples of the LMC and, eventually, the SMC.

  10. METAPOPULATION STRUCTURE AND DYNAMICS OF POND BREEDING

    EPA Science Inventory

    Our review indicates that pond breeding amphibians exhibit highly variable spatial and temporal population dynamics, such that no single generalized model can realistically describe these animals. We propose that consideration of breeding pond permanence, and adaptations to pond ...

  11. Simulations reveal the power and peril of artificial breeding sites for monitoring and managing animals.

    PubMed

    McClure, Christopher J W; Pauli, Benjamin P; Heath, Julie A

    2017-01-24

    Despite common use, the efficacy of artificial breeding sites (e.g., nest boxes, bat houses, artificial burrows) as tools for monitoring and managing animals depends on the demography of target populations and availability of natural sites. Yet, the conditions enabling artificial breeding sites to be useful or informative have yet to be articulated. We use a stochastic simulation model to determine situations where artificial breeding sites are either useful or disadvantageous for monitoring and managing animals. Artificial breeding sites are a convenient tool for monitoring animals and therefore occupancy of artificial breeding sites is often used as an index of population levels. However, systematic changes in availability of sites that are not monitored might induce trends in occupancy of monitored sites-a situation rarely considered by monitoring programs. We therefore examine how systematic changes in unmonitored sites could bias inference from trends in the occupancy of monitored sites. Our model also allows us to examine effects on population levels if artificial breeding sites either increase or decrease population vital rates (survival and fecundity). We demonstrate that trends in occupancy of monitored sites are misleading if the number of unmonitored sites changes over time. Further, breeding site fidelity can cause an initial lag in occupancy of newly installed sites that could be misinterpreted as an increasing population, even when the population has been continuously declining. Importantly, provisioning of artificial breeding sites only benefits populations if breeding sites are limiting or if artificial sites increase vital rates. There are many situations where installation of artificial breeding sites, and their use in monitoring, can have unintended consequences. Managers should therefore not assume that provision of artificial breeding sites will necessarily benefit populations. Further, trends in occupancy of artificial breeding sites should be

  12. Primordial evolvability: Impasses and challenges.

    PubMed

    Vasas, Vera; Fernando, Chrisantha; Szilágyi, András; Zachár, István; Santos, Mauro; Szathmáry, Eörs

    2015-09-21

    While it is generally agreed that some kind of replicating non-living compounds were the precursors of life, there is much debate over their possible chemical nature. Metabolism-first approaches propose that mutually catalytic sets of simple organic molecules could be capable of self-replication and rudimentary chemical evolution. In particular, the graded autocatalysis replication domain (GARD) model, depicting assemblies of amphiphilic molecules, has received considerable interest. The system propagates compositional information across generations and is suggested to be a target of natural selection. However, evolutionary simulations indicate that the system lacks selectability (i.e. selection has negligible effect on the equilibrium concentrations). We elaborate on the lessons learnt from the example of the GARD model and, more widely, on the issue of evolvability, and discuss the implications for similar metabolism-first scenarios. We found that simple incorporation-type chemistry based on non-covalent bonds, as assumed in GARD, is unlikely to result in alternative autocatalytic cycles when catalytic interactions are randomly distributed. An even more serious problem stems from the lognormal distribution of catalytic factors, causing inherent kinetic instability of such loops, due to the dominance of efficiently catalyzed components that fail to return catalytic aid. Accordingly, the dynamics of the GARD model is dominated by strongly catalytic, but not auto-catalytic, molecules. Without effective autocatalysis, stable hereditary propagation is not possible. Many repetitions and different scaling of the model come to no rescue. Despite all attempts to show the contrary, the GARD model is not evolvable, in contrast to reflexively autocatalytic networks, complemented by rare uncatalyzed reactions and compartmentation. The latter networks, resting on the creation and breakage of chemical bonds, can generate novel ('mutant') autocatalytic loops from a given set of

  13. Can I compare EPD's across breeds?

    USDA-ARS?s Scientific Manuscript database

    Proper comparison of the genetic merit of animals across breeds can be difficult and confusion for beef cattle producers. With the advent of a new genetic evaluation system where several breeds are evaluated in the same genetic analysis, confusion on direct comparison of animals across breeds has i...

  14. Population structure of ice-breeding seals.

    PubMed

    Davis, Corey S; Stirling, Ian; Strobeck, Curtis; Coltman, David W

    2008-07-01

    The development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. Species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. Other aspects of life history such as geographically distinct vocalizations, female gregariousness, and the potential for polygynous breeding may also facilitate population structure. Based on these factors, we predicted that fast-ice-breeding seal species (the Weddell and ringed seal) would show elevated genetic differentiation compared to pack-ice-breeding species (the leopard, Ross, crabeater and bearded seals). We tested this prediction using microsatellite analysis to examine population structure of these six ice-breeding species. Our results did not support this prediction. While none of the Antarctic pack-ice species showed statistically significant population structure, the bearded seal of the Arctic pack ice showed strong differentiation between subpopulations. Again in contrast, the fast-ice-breeding Weddell seal of the Antarctic showed clear evidence for genetic differentiation while the ringed seal, breeding in similar habitat in the Arctic, did not. These results suggest that the development of population structure in ice-breeding phocid seals is a more complex outcome of the interplay of phylogenetic and ecological factors than can be predicted on the basis of breeding substrate and life-history characteristics.

  15. Genetic Diversity of US Sheep Breeds

    USDA-ARS?s Scientific Manuscript database

    Understanding the genetic relationships between US sheep breeds is useful in developing conservation strategies and actions. A broad sampling of individual sheep from 28 breeds was performed. Breed types included: fine wool, meat types, long wool, hair, prolific, and fat tailed. Blood and semen samp...

  16. Evolving phenotype of Marfan's syndrome

    PubMed Central

    Lipscomb, K.; Clayton-Smith, J.; Harris, R.

    1997-01-01

    Accepted 20 August 1996
 AIM—To examine evolution of the physical characteristics of Marfan's syndrome throughout childhood.
METHODS—40 children were ascertained during the development of a regional register for Marfan's syndrome. Evolution of the clinical characteristics was determined by repeat evaluation of 10 patients with sporadic Marfan's syndrome and 30 with a family history of the condition. DNA marker studies were used to facilitate diagnosis in those with the familial condition.
RESULTS—Musculoskeletal features predominated and evolved throughout childhood. Gene tracking enabled early diagnosis in children with familial Marfan's syndrome.
CONCLUSIONS—These observations may aid the clinical diagnosis of Marfan's syndrome in childhood, especially in those with the sporadic condition. Gene tracking has a role in the early diagnosis of familial Marfan's syndrome, allowing appropriate follow up and preventive care.

 PMID:9059160

  17. Isotopic Analysis and Evolved Gases

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.; Boynton, William V.; Chutjian, Ara; Hoffman, John H.; Jordan, Jim L.; Kargel, Jeffrey S.; McEntire, Richard W.; Nyquist, Larry

    1996-01-01

    Precise measurements of the chemical, elemental, and isotopic composition of planetary surface material and gases, and observed variations in these compositions, can contribute significantly to our knowledge of the source(s), ages, and evolution of solar system materials. The analyses discussed in this paper are mostly made by mass spectrometers or some other type of mass analyzer, and address three broad areas of interest: (1) atmospheric composition - isotopic, elemental, and molecular, (2) gases evolved from solids, and (3) solids. Current isotopic data on nine elements, mostly from in situ analysis, but also from meteorites and telescopic observations are summarized. Potential instruments for isotopic analysis of lunar, Martian, Venusian, Mercury, and Pluto surfaces, along with asteroid, cometary and icy satellites, surfaces are discussed.

  18. [The evolving of cardiac interventions].

    PubMed

    Billinger, Michael

    2014-12-01

    Treatment modalities for heart diseases have considerable evolved during the last 20 years. Coronary and valvular heart disease are treated increasingly by less invasive percutaneous catheter based procedures instead of open-heart surgery. In addition, new cutting-edge interventions allow to cure heart disease for which until recently only medical treatment options were available. Whilst many patients benefit from these innovative therapies, rapidly developing technologies potentially carry the risk of overtreatment. In order to select patients for the most appropriate treatment, an intensive interdisciplinary teamwork between cardiologists and cardiac surgeons is a mandatory requirement. Additionally, knowledge transfer between cardiologists, their growing subspecialties and practitioners should be encouraged. Finally, timely scientific evaluation of new therapies and subsequent incorporation in guidelines remains crucial.

  19. Rapidly evolving homing CRISPR barcodes.

    PubMed

    Kalhor, Reza; Mali, Prashant; Church, George M

    2017-02-01

    We present an approach for engineering evolving DNA barcodes in living cells. A homing guide RNA (hgRNA) scaffold directs the Cas9-hgRNA complex to the DNA locus of the hgRNA itself. We show that this homing CRISPR-Cas9 system acts as an expressed genetic barcode that diversifies its sequence and that the rate of diversification can be controlled in cultured cells. We further evaluate these barcodes in cell populations and show that they can be used to record lineage history and that the barcode RNA can be amplified in situ, a prerequisite for in situ sequencing. This integrated approach will have wide-ranging applications, such as in deep lineage tracing, cellular barcoding, molecular recording, dissecting cancer biology, and connectome mapping.

  20. The evolving Gleason grading system.

    PubMed

    Chen, Ni; Zhou, Qiao

    2016-02-01

    The Gleason grading system for prostate adenocarcinoma has evolved from its original scheme established in the 1960s-1970s, to a significantly modified system after two major consensus meetings conducted by the International Society of Urologic Pathology (ISUP) in 2005 and 2014, respectively. The Gleason grading system has been incorporated into the WHO classification of prostate cancer, the AJCC/UICC staging system, and the NCCN guidelines as one of the key factors in treatment decision. Both pathologists and clinicians need to fully understand the principles and practice of this grading system. We here briefly review the historical aspects of the original scheme and the recent developments of Gleason grading system, focusing on major changes over the years that resulted in the modern Gleason grading system, which has led to a new "Grade Group" system proposed by the 2014 ISUP consensus, and adopted by the 2016 WHO classification of tumours of the prostate.

  1. The evolving Gleason grading system

    PubMed Central

    Chen, Ni

    2016-01-01

    The Gleason grading system for prostate adenocarcinoma has evolved from its original scheme established in the 1960s–1970s, to a significantly modified system after two major consensus meetings conducted by the International Society of Urologic Pathology (ISUP) in 2005 and 2014, respectively. The Gleason grading system has been incorporated into the WHO classification of prostate cancer, the AJCC/UICC staging system, and the NCCN guidelines as one of the key factors in treatment decision. Both pathologists and clinicians need to fully understand the principles and practice of this grading system. We here briefly review the historical aspects of the original scheme and the recent developments of Gleason grading system, focusing on major changes over the years that resulted in the modern Gleason grading system, which has led to a new “Grade Group” system proposed by the 2014 ISUP consensus, and adopted by the 2016 WHO classification of tumours of the prostate. PMID:27041927

  2. Evolving networks by merging cliques

    NASA Astrophysics Data System (ADS)

    Takemoto, Kazuhiro; Oosawa, Chikoo

    2005-10-01

    We propose a model for evolving networks by merging building blocks represented as complete graphs, reminiscent of modules in biological system or communities in sociology. The model shows power-law degree distributions, power-law clustering spectra, and high average clustering coefficients independent of network size. The analytical solutions indicate that a degree exponent is determined by the ratio of the number of merging nodes to that of all nodes in the blocks, demonstrating that the exponent is tunable, and are also applicable when the blocks are classical networks such as Erdös-Rényi or regular graphs. Our model becomes the same model as the Barabási-Albert model under a specific condition.

  3. Behavioural plasticity in evolving robots.

    PubMed

    Carvalho, Jônata Tyska; Nolfi, Stefano

    2016-12-01

    In this paper, we show how the development of plastic behaviours, i.e., behaviour displaying a modular organisation characterised by behavioural subunits that are alternated in a context-dependent manner, can enable evolving robots to solve their adaptive task more efficiently also when it does not require the accomplishment of multiple conflicting functions. The comparison of the results obtained in different experimental conditions indicates that the most important prerequisites for the evolution of behavioural plasticity are: the possibility to generate and perceive affordances (i.e., opportunities for behaviour execution), the possibility to rely on flexible regulatory processes that exploit both external and internal cues, and the possibility to realise smooth and effective transitions between behaviours.

  4. Speech processing: An evolving technology

    SciTech Connect

    Crochiere, R.E.; Flanagan, J.L.

    1986-09-01

    As we enter the information age, speech processing is emerging as an important technology for making machines easier and more convenient for humans to use. It is both an old and a new technology - dating back to the invention of the telephone and forward, at least in aspirations, to the capabilities of HAL in 2001. Explosive advances in microelectronics now make it possible to implement economical real-time hardware for sophisticated speech processing - processing that formerly could be demonstrated only in simulations on main-frame computers. As a result, fundamentally new product concepts - as well as new features and functions in existing products - are becoming possible and are being explored in the marketplace. As the introductory piece to this issue, the authors draw a brief perspective on the evolving field of speech processing and assess the technology in the the three constituent sectors: speech coding, synthesis, and recognition.

  5. Evolving Localizations in Reaction-Diffusion Cellular Automata

    NASA Astrophysics Data System (ADS)

    Adamatzky, Andrew; Bull, Larry; Collet, Pierre; Sapin, Emmanuel

    We consider hexagonal cellular automata with immediate cell neighbourhood and three cell-states. Every cell calculates its next state depending on the integral representation of states in its neighbourhood, i.e., how many neighbours are in each one state. We employ evolutionary algorithms to breed local transition functions that support mobile localizations (gliders), and characterize sets of the functions selected in terms of quasi-chemical systems. Analysis of the set of functions evolved allows to speculate that mobile localizations are likely to emerge in the quasi-chemical systems with limited diffusion of one reagent, a small number of molecules are required for amplification of travelling localizations, and reactions leading to stationary localizations involve relatively equal amount of quasi-chemical species. Techniques developed can be applied in cascading signals in nature-inspired spatially extended computing devices, and phenomenological studies and classification of non-linear discrete systems.

  6. [The evaluation of breed-specific defects in dog breeds from an animal welfare viewpoint].

    PubMed

    Peyer, N; Steiger, A

    1998-01-01

    Issues of breed defects such as morphology, physiology or behaviour in pure-breed dogs, are briefly discussed. Suggestions for various kinds of improvements are made, particularly concerning legislation, analysis of pedigree to avoid undesirable breed characteristics and what breeding clubs, individual breeders, judges, future dog owners and veterinarians could and should do about these problems; these are followed by summary conclusions.

  7. A simple language to script and simulate breeding schemes: the breeding scheme language

    USDA-ARS?s Scientific Manuscript database

    It is difficult for plant breeders to determine an optimal breeding strategy given that the problem involves many factors, such as target trait genetic architecture and breeding resource availability. There are many possible breeding schemes for each breeding program. Although simulation study may b...

  8. Emperor Penguins Breeding on Iceshelves

    PubMed Central

    Fretwell, Peter T.; Trathan, Phil N.; Wienecke, Barbara; Kooyman, Gerald L.

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin’s reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as “near threatened” in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species. PMID:24416381

  9. Evolution of Conspecific Brood Parasitism versus Cooperative Breeding as Alternative Reproductive Tactics.

    PubMed

    Zink, Andrew G; Lyon, Bruce E

    2016-01-01

    Cooperative breeding and conspecific brood parasitism can both be favored by ecological saturation of breeding territories or nest sites. Here, we develop a model that links these alternative reproductive tactics by focusing on nonnesting females (S) that either breed cooperatively with a nesting female (N) or parasitize a third, outside host female (H). We find that cooperative breeding is more likely to evolve with increasing relatedness of cooperating females (S or N) to the outside host female (H) and with increasing costs to the hosts for receiving parasitic eggs. Conversely, cooperation is less likely with increasing kinship between the two potentially cooperative nesters (S and N). This is because even the nesting female gains higher inclusive fitness as long as the number of parasitic eggs (of her otherwise potentially cooperating partner) is sufficiently high. We find the relationship between kinship and reproductive skew within cooperative nests can be either positive or negative depending on the fecundity of parasites versus nesting females. We also find that either of the cooperatively nesting females is more likely to tolerate a smaller fraction of group reproduction as kinship with the host female increases and as the host reproduces more (relative to the parasite) in outside nests. Finally, our model predicts that, as the outside option of conspecific brood parasitism becomes more profitable, helping behavior (zero reproduction by one female) is less likely to evolve in cooperatively breeding groups.

  10. Antipredator strategies in breeding Bristle-thighed Curlews

    USGS Publications Warehouse

    McCaffery, Brian J.; Gill, Robert E.

    1992-01-01

    Each fall the world’s breeding population of Bristle-thighed Curlews (Numenius tahitiensis) arrives on the central Pacific wintering grounds following a migration that entails a non- stop flight of over 5000 kilometers. Sun-drenched, palm-shrouded atolls will be their home for the ensuing eight months. Even in the avian world, however, such apparant luxury is not without costs. For the Bristle-thighed Curlew these costs are incurred on the breeding grounds. From the time they arrive there in early May until they depart again for the wintering grounds in August and September, curlews are exposed to a host of predators. Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), Northern Harriers (Circus cyaneus), Parasitic Jaegers (Stercorarius parasiticus), Short-eared Owls (Asio flammeus), Common Ravens (Corvus corax) and Red Foxes (Vulpes vulpes) are potential predators of curlews and their offspring. To combat these threats, the Bristle-thighed Curlew has evolved an elaborate suite of antipredator defenses. Depending on the threat and the phase of the breeding cycle, Bristle-thighed Curlews may respond to potential predators by fleeing or flocking, by camouflage or combat. Given the variety of predators on the tundra, a variety of options is critical.

  11. Beyond promiscuity: mate-choice commitments in social breeding

    PubMed Central

    Boomsma, Jacobus J.

    2013-01-01

    Obligate eusociality with distinct caste phenotypes has evolved from strictly monogamous sub-social ancestors in ants, some bees, some wasps and some termites. This implies that no lineage reached the most advanced form of social breeding, unless helpers at the nest gained indirect fitness values via siblings that were identical to direct fitness via offspring. The complete lack of re-mating promiscuity equalizes sex-specific variances in reproductive success. Later, evolutionary developments towards multiple queen-mating retained lifetime commitment between sexual partners, but reduced male variance in reproductive success relative to female's, similar to the most advanced vertebrate cooperative breeders. Here, I (i) discuss some of the unique and highly peculiar mating system adaptations of eusocial insects; (ii) address ambiguities that remained after earlier reviews and extend the monogamy logic to the evolution of soldier castes; (iii) evaluate the evidence for indirect fitness benefits driving the dynamics of (in)vertebrate cooperative breeding, while emphasizing the fundamental differences between obligate eusociality and cooperative breeding; (iv) infer that lifetime commitment is a major driver towards higher levels of organization in bodies, colonies and mutualisms. I argue that evolutionary informative definitions of social systems that separate direct and indirect fitness benefits facilitate transparency when testing inclusive fitness theory. PMID:23339241

  12. Assortative mating and fragmentation within dog breeds.

    PubMed

    Björnerfeldt, Susanne; Hailer, Frank; Nord, Maria; Vilà, Carles

    2008-01-28

    There are around 400 internationally recognized dog breeds in the world today, with a remarkable diversity in size, shape, color and behavior. Breeds are considered to be uniform groups with similar physical characteristics, shaped by selection rooted in human preferences. This has led to a large genetic difference between breeds and a large extent of linkage disequilibrium within breeds. These characteristics are important for association mapping of candidate genes for diseases and therefore make dogs ideal models for gene mapping of human disorders. However, genetic uniformity within breeds may not always be the case. We studied patterns of genetic diversity within 164 poodles and compared it to 133 dogs from eight other breeds. Our analyses revealed strong population structure within poodles, with differences among some poodle groups as pronounced as those among other well-recognized breeds. Pedigree analysis going three generations back in time confirmed that subgroups within poodles result from assortative mating imposed by breed standards as well as breeder preferences. Matings have not taken place at random or within traditionally identified size classes in poodles. Instead, a novel set of five poodle groups was identified, defined by combinations of size and color, which is not officially recognized by the kennel clubs. Patterns of genetic diversity in other breeds suggest that assortative mating leading to fragmentation may be a common feature within many dog breeds. The genetic structure observed in poodles is the result of local mating patterns, implying that breed fragmentation may be different in different countries. Such pronounced structuring within dog breeds can increase the power of association mapping studies, but also represents a serious problem if ignored. In dog breeding, individuals are selected on the basis of morphology, behaviour, working or show purposes, as well as geographic population structure. The same processes which have

  13. Assortative mating and fragmentation within dog breeds

    PubMed Central

    2008-01-01

    Background There are around 400 internationally recognized dog breeds in the world today, with a remarkable diversity in size, shape, color and behavior. Breeds are considered to be uniform groups with similar physical characteristics, shaped by selection rooted in human preferences. This has led to a large genetic difference between breeds and a large extent of linkage disequilibrium within breeds. These characteristics are important for association mapping of candidate genes for diseases and therefore make dogs ideal models for gene mapping of human disorders. However, genetic uniformity within breeds may not always be the case. We studied patterns of genetic diversity within 164 poodles and compared it to 133 dogs from eight other breeds. Results Our analyses revealed strong population structure within poodles, with differences among some poodle groups as pronounced as those among other well-recognized breeds. Pedigree analysis going three generations back in time confirmed that subgroups within poodles result from assortative mating imposed by breed standards as well as breeder preferences. Matings have not taken place at random or within traditionally identified size classes in poodles. Instead, a novel set of five poodle groups was identified, defined by combinations of size and color, which is not officially recognized by the kennel clubs. Patterns of genetic diversity in other breeds suggest that assortative mating leading to fragmentation may be a common feature within many dog breeds. Conclusion The genetic structure observed in poodles is the result of local mating patterns, implying that breed fragmentation may be different in different countries. Such pronounced structuring within dog breeds can increase the power of association mapping studies, but also represents a serious problem if ignored. In dog breeding, individuals are selected on the basis of morphology, behaviour, working or show purposes, as well as geographic population structure. The same

  14. Microbiome Selection Could Spur Next-Generation Plant Breeding Strategies

    PubMed Central

    Gopal, Murali; Gupta, Alka

    2016-01-01

    “No plant is an island too…” Plants, though sessile, have developed a unique strategy to counter biotic and abiotic stresses by symbiotically co-evolving with microorganisms and tapping into their genome for this purpose. Soil is the bank of microbial diversity from which a plant selectively sources its microbiome to suit its needs. Besides soil, seeds, which carry the genetic blueprint of plants during trans-generational propagation, are home to diverse microbiota that acts as the principal source of microbial inoculum in crop cultivation. Overall, a plant is ensconced both on the outside and inside with a diverse assemblage of microbiota. Together, the plant genome and the genes of the microbiota that the plant harbors in different plant tissues, i.e., the ‘plant microbiome,’ form the holobiome which is now considered as unit of selection: ‘the holobiont.’ The ‘plant microbiome’ not only helps plants to remain fit but also offers critical genetic variability, hitherto, not employed in the breeding strategy by plant breeders, who traditionally have exploited the genetic variability of the host for developing high yielding or disease tolerant or drought resistant varieties. This fresh knowledge of the microbiome, particularly of the rhizosphere, offering genetic variability to plants, opens up new horizons for breeding that could usher in cultivation of next-generation crops depending less on inorganic inputs, resistant to insect pest and diseases and resilient to climatic perturbations. We surmise, from ever increasing evidences, that plants and their microbial symbionts need to be co-propagated as life-long partners in future strategies for plant breeding. In this perspective, we propose bottom–up approach to co-propagate the co-evolved, the plant along with the target microbiome, through – (i) reciprocal soil transplantation method, or (ii) artificial ecosystem selection method of synthetic microbiome inocula, or (iii) by exploration of

  15. Microbiome Selection Could Spur Next-Generation Plant Breeding Strategies.

    PubMed

    Gopal, Murali; Gupta, Alka

    2016-01-01

    "No plant is an island too…" Plants, though sessile, have developed a unique strategy to counter biotic and abiotic stresses by symbiotically co-evolving with microorganisms and tapping into their genome for this purpose. Soil is the bank of microbial diversity from which a plant selectively sources its microbiome to suit its needs. Besides soil, seeds, which carry the genetic blueprint of plants during trans-generational propagation, are home to diverse microbiota that acts as the principal source of microbial inoculum in crop cultivation. Overall, a plant is ensconced both on the outside and inside with a diverse assemblage of microbiota. Together, the plant genome and the genes of the microbiota that the plant harbors in different plant tissues, i.e., the 'plant microbiome,' form the holobiome which is now considered as unit of selection: 'the holobiont.' The 'plant microbiome' not only helps plants to remain fit but also offers critical genetic variability, hitherto, not employed in the breeding strategy by plant breeders, who traditionally have exploited the genetic variability of the host for developing high yielding or disease tolerant or drought resistant varieties. This fresh knowledge of the microbiome, particularly of the rhizosphere, offering genetic variability to plants, opens up new horizons for breeding that could usher in cultivation of next-generation crops depending less on inorganic inputs, resistant to insect pest and diseases and resilient to climatic perturbations. We surmise, from ever increasing evidences, that plants and their microbial symbionts need to be co-propagated as life-long partners in future strategies for plant breeding. In this perspective, we propose bottom-up approach to co-propagate the co-evolved, the plant along with the target microbiome, through - (i) reciprocal soil transplantation method, or (ii) artificial ecosystem selection method of synthetic microbiome inocula, or (iii) by exploration of microRNA transfer

  16. Production objectives, trait and breed preferences of farmers keeping N'Dama, Fulani Zebu and crossbred cattle and implications for breeding programs.

    PubMed

    Traoré, S A; Markemann, A; Reiber, C; Piepho, H P; Valle Zárate, A

    2017-04-01

    Many local livestock breeds in developing countries are being replaced by exotic breeds, leading to a loss of genetic resources. In southern Mali, for the past two decades, a trend towards increasing crossbreeding between the trypanotolerant N'Dama cattle and the trypano-susceptible Fulani Zebu cattle has been taking place. A survey with 160 farmers owning a cattle herd was carried out in southern Mali to investigate their production objectives, as well as trait and breed preferences and correlated socio-economic determinants in order to understand farmers' breeding decisions and to identify comparative advantages of three breed groups (N'Dama, Fulani Zebu and crossbreds) raised in the study area. Data were analyzed using an exploded logit model. The reasons for raising cattle, as well as trait and breed preferences reflected the multiple objectives of the farmers. Draught power and savings were the most important production objectives. Productive traits were ranked highest; farmers reported large body size as the most preferred trait, followed by fertility, draught ability and milk yield. Crossbreds were the favored breed group. Breed preferences were mainly explained by 'resistance to disease' for N'Dama cattle and 'high market price' for Fulani Zebu and crossbred cattle. Production objectives, trait and breed preferences were mainly influenced by farmer group (local farmers and settled transhumants). Local farmers put comparatively more emphasis on livestock functions linked to crop production such as draught power. They had a higher preference for traction ability as a selection trait and preferred N'Dama over Fulani Zebu cattle. Settled transhumants emphasized milk yield as a selection trait and preferred Fulani Zebu over N'Dama. The results indicate that the trend towards more crossbreeding will continue putting the N'Dama breed under high risk of genetic dilution in southern Mali. The N'Dama cattle remain a valuable breed due to their adaptive traits such as

  17. Limitations of captive breeding in endangered species recovery

    USGS Publications Warehouse

    Snyder, N.F.R.; Derrickson, S.R.; Beissenger, S.R.; Wiley, J.W.; Smith, T.B.; Toone, W.D.; Miller, B.

    1996-01-01

    The use of captive breeding in species recovery has grown enormously in recent years, but without a concurrent growth in appreciation of its limitations. Problems with (1) establishing self-sufficient captive populations, (2) poor success in reintroductions, (3.) high costs, (4) domestication, (5) preemption of other recovery techniques, (6) disease outbreaks, and (7) maintaining administrative continuity have all been significant. The technique has often been invoked prematurely and should not normally be employed before a careful field evaluation of costs and benefits of all conservation alternatives has been accomplished and a determination made that captive breeding is essential for species survival. Merely demonstrating that a species population is declining or bas fallen below what may be a minimum viable size does not constitute enough analysis to justify captive breeding as a recovery measure. Captive breeding should be reviewed as a last resort in species recovery and not a prophylactic or long-term solution because of the inexorable genetic and phenotypic changes that occur in captive environments. Captive breeding can play a crucial role in recovery of some species for witch effective alternatives are unavailable in the short term. However, it should not displace habitat and ecosystem protection nor should it be invoked in the absence of comprehensive efforts to maintain or restore populations in wild habitats. Zoological institutions with captive breeding programs should operate under carefully defined conditions of disease prevention and genetic/behavioral management. More important, these institutions should help preserve biodiversity through their capacities for public education, professional training, research, and support of in situ conservation efforts.

  18. Evolving roles of highly successful mentors.

    PubMed

    Melanson, Mark A

    2007-01-01

    This article was written groom mentors, old and new, by identifying the evolving roles that highly successful mentors in order to share wisdom with their protégés. First aspiring mentors need to become subject matter experts in their profession by achieving the relevant benchmarks of mastery in their career fields. Next, they must win the coveted role of respected leader by being trustworthy and putting the development of others first. The mastery of knowledge and earning of respect must also be balanced by genuine humility if the mentor is to be effective in sharing what he or she knows. Highly successful mentors are teachers, plain and simple, and they are most effective in this role when they have a deep passion for teaching. By properly using reflection, adroit mentors look back upon their many adventures and carefully select critical stories to share with their protégés. While outstanding mentors have a lot to say, they need to spend most of their time listening to those they mentor to ensure that they understand their protégés' individualized needs and goals. To help protégés through the setbacks and disappointments that can accompany an Army career, high-speed mentors need to don the role of optimistic cheerleaders, encouraging those they mentor and restoring hope. Once a striving mentor has finally reached the summit of mentoring and is a trusted counselor, he or she must continue to nurture and protect this fragile, but most influential role. Lastly, great mentors need to be consummate students of both their profession and mentoring so that they remain vital and responsive to those they mentor. In closing, it is hoped that by considering and embracing these evolving roles, dedicated students of mentoring will derive a deeper satisfaction and have greater success in this critically important leadership responsibility.

  19. Evaluation of the stallion for breeding soundness.

    PubMed

    Hurtgen, J P

    1992-04-01

    The breeding soundness evaluation of a stallion is a thorough investigation of a stallion's libido, mating ability, and semen quality. The evaluation should include historical data about the medical aspects of the horse's performance and breeding career, observations and breeding behavior characteristics, collection and evaluation of semen, tests to determine freedom from infectious or contagious disease, and production of foals free of genetic defects. This information should allow the examiner to anticipate the impact of the stallion on the reproductive efficiency of a group of mares. The breeding soundness evaluation should also assist farm management in optimizing stallion, mare, veterinary, and management influences on total herd breeding performance.

  20. A Quantitative Approach to Assessing System Evolvability

    NASA Technical Reports Server (NTRS)

    Christian, John A., III

    2004-01-01

    When selecting a system from multiple candidates, the customer seeks the one that best meets his or her needs. Recently the desire for evolvable systems has become more important and engineers are striving to develop systems that accommodate this need. In response to this search for evolvability, we present a historical perspective on evolvability, propose a refined definition of evolvability, and develop a quantitative method for measuring this property. We address this quantitative methodology from both a theoretical and practical perspective. This quantitative model is then applied to the problem of evolving a lunar mission to a Mars mission as a case study.

  1. Migratory double breeding in Neotropical migrant birds

    PubMed Central

    Rohwer, Sievert; Hobson, Keith A.; Rohwer, Vanya G.

    2009-01-01

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants. PMID:19858484

  2. Migratory double breeding in Neotropical migrant birds.

    PubMed

    Rohwer, Sievert; Hobson, Keith A; Rohwer, Vanya G

    2009-11-10

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants.

  3. Increased longevity evolves from grandmothering.

    PubMed

    Kim, Peter S; Coxworth, James E; Hawkes, Kristen

    2012-12-22

    Postmenopausal longevity may have evolved in our lineage when ancestral grandmothers subsidized their daughters' fertility by provisioning grandchildren, but the verbal hypothesis has lacked mathematical support until now. Here, we present a formal simulation in which life spans similar to those of modern chimpanzees lengthen into the modern human range as a consequence of grandmother effects. Greater longevity raises the chance of living through the fertile years but is opposed by costs that differ for the sexes. Our grandmother assumptions are restrictive. Only females who are no longer fertile themselves are eligible, and female fertility extends to age 45 years. Initially, there are very few eligible grandmothers and effects are small. Grandmothers can support only one dependent at a time and do not care selectively for their daughters' offspring. They must take the oldest juveniles still relying on mothers; and infants under the age of 2 years are never eligible for subsidy. Our model includes no assumptions about brains, learning or pair bonds. Grandmother effects alone are sufficient to propel the doubling of life spans in less than sixty thousand years.

  4. Circumstellar Crystalline Silicates: Evolved Stars

    NASA Astrophysics Data System (ADS)

    Tartar, Josh; Speck, A. K.

    2008-05-01

    One of the most exciting developments in astronomy in the last 15 years was the discovery of crystalline silicate stardust by the Short Wavelength Spectrometer (SWS) on board of ISO; discovery of the crystalline grains was indeed one of the biggest surprises of the ISO mission. Initially discovered around AGB stars (evolved stars in the range of 0.8 > M/M¤>8) at far-infrared (IR) wavelengths, crystalline silicates have since been seen in many astrophysical environments including young stellar objects (T Tauri and Herbig Ae/Be), comets and Ultra Luminous Infrared Galaxies. Low and intermediate mass stars (LIMS) comprise 95% of the contributors to the ISM, so study of the formation of crystalline silicates is critical to our understanding of the ISM, which is thought to be primarily amorphous (one would expect an almost exact match between the composition of AGB dust shells and the dust in the ISM). Whether the crystalline dust is merely undetectable or amorphized remains a mystery. The FORCAST instrument on SOFIA as well as the PACS instrument on Herschel will provide exciting observing opportunities for the further study of crystalline silicates.

  5. Multicopy Suppression Underpins Metabolic Evolvability

    PubMed Central

    Patrick, Wayne M.; Quandt, Erik M.; Swartzlander, Dan B.; Matsumura, Ichiro

    2009-01-01

    Our understanding of the origins of new metabolic functions is based upon anecdotal genetic and biochemical evidence. Some auxotrophies can be suppressed by overexpressing substrate-ambiguous enzymes (i.e., those that catalyze the same chemical transformation on different substrates). Other enzymes exhibit weak but detectable catalytic promiscuity in vitro (i.e., they catalyze different transformations on similar substrates). Cells adapt to novel environments through the evolution of these secondary activities, but neither their chemical natures nor their frequencies of occurrence have been characterized en bloc. Here, we systematically identified multifunctional genes within the Escherichia coli genome. We screened 104 single-gene knockout strains and discovered that many (20%) of these auxotrophs were rescued by the overexpression of at least one noncognate E. coli gene. The deleted gene and its suppressor were generally unrelated, suggesting that promiscuity is a product of contingency. This genome-wide survey demonstrates that multifunctional genes are common and illustrates the mechanistic diversity by which their products enhance metabolic robustness and evolvability. PMID:17884825

  6. Magnetic fields around evolved stars

    NASA Astrophysics Data System (ADS)

    Leal-Ferreira, M.; Vlemmings, W.; Kemball, A.; Amiri, N.; Maercker, M.; Ramstedt, S.; Olofsson, G.

    2014-04-01

    A number of mechanisms, such as magnetic fields, (binary) companions and circumstellar disks have been suggested to be the cause of non-spherical PNe and in particular collimated outflows. This work investigates one of these mechanisms: the magnetic fields. While MHD simulations show that the fields can indeed be important, few observations of magnetic fields have been done so far. We used the VLBA to observe five evolved stars, with the goal of detecting the magnetic field by means of water maser polarization. The sample consists in four AGB stars (IK Tau, RT Vir, IRC+60370 and AP Lyn) and one pPN (OH231.8+4.2). In four of the five sources, several strong maser features were detected allowing us to measure the linear and/or circular polarization. Based on the circular polarization detections, we infer the strength of the component of the field along the line of sight to be between ~30 mG and ~330 mG in the water maser regions of these four sources. When extrapolated to the surface of the stars, the magnetic field strength would be between a few hundred mG and a few Gauss when assuming a toroidal field geometry and higher when assuming more complex magnetic fields. We conclude that the magnetic energy we derived in the water maser regions is higher than the thermal and kinetic energy, leading to the conclusion that, indeed, magnetic fields probably play an important role in shaping Planetary Nebulae.

  7. How do drumlin patterns evolve?

    NASA Astrophysics Data System (ADS)

    Ely, Jeremy; Clark, Chris; Spagnolo, Matteo; Hughes, Anna

    2016-04-01

    The flow of a geomorphic agent over a sediment bed creates patterns in the substrate composed of bedforms. Ice is no exception to this, organising soft sedimentary substrates into subglacial bedforms. As we are yet to fully observe their initiation and evolution beneath a contemporary ice mass, little is known about how patterns in subglacial bedforms develop. Here we study 36,222 drumlins, divided into 72 flowsets, left behind by the former British-Irish Ice sheet. These flowsets provide us with 'snapshots' of drumlin pattern development. The probability distribution functions of the size and shape metrics of drumlins within these flowsets were analysed to determine whether behaviour that is common of other patterned phenomena has occurred. Specifically, we ask whether drumlins i) are printed at a specific scale; ii) grow or shrink after they initiate; iii) stabilise at a specific size and shape; and iv) migrate. Our results indicate that drumlins initiate at a minimum size and spacing. After initiation, the log-normal distribution of drumlin size and shape metrics suggests that drumlins grow, or possibly shrink, as they develop. We find no evidence for stabilisation in drumlin length, supporting the idea of a subglacial bedform continuum. Drumlin migration is difficult to determine from the palaeo-record. However, there are some indications that a mixture of static and mobile drumlins occurs, which could potentially lead to collisions, cannibalisation and coarsening. Further images of modern drumlin fields evolving beneath ice are required to capture stages of drumlin pattern evolution.

  8. Increased longevity evolves from grandmothering

    PubMed Central

    Kim, Peter S.; Coxworth, James E.; Hawkes, Kristen

    2012-01-01

    Postmenopausal longevity may have evolved in our lineage when ancestral grandmothers subsidized their daughters' fertility by provisioning grandchildren, but the verbal hypothesis has lacked mathematical support until now. Here, we present a formal simulation in which life spans similar to those of modern chimpanzees lengthen into the modern human range as a consequence of grandmother effects. Greater longevity raises the chance of living through the fertile years but is opposed by costs that differ for the sexes. Our grandmother assumptions are restrictive. Only females who are no longer fertile themselves are eligible, and female fertility extends to age 45 years. Initially, there are very few eligible grandmothers and effects are small. Grandmothers can support only one dependent at a time and do not care selectively for their daughters' offspring. They must take the oldest juveniles still relying on mothers; and infants under the age of 2 years are never eligible for subsidy. Our model includes no assumptions about brains, learning or pair bonds. Grandmother effects alone are sufficient to propel the doubling of life spans in less than sixty thousand years. PMID:23097518

  9. Recommendation in evolving online networks

    NASA Astrophysics Data System (ADS)

    Hu, Xiao; Zeng, An; Shang, Ming-Sheng

    2016-02-01

    Recommender system is an effective tool to find the most relevant information for online users. By analyzing the historical selection records of users, recommender system predicts the most likely future links in the user-item network and accordingly constructs a personalized recommendation list for each user. So far, the recommendation process is mostly investigated in static user-item networks. In this paper, we propose a model which allows us to examine the performance of the state-of-the-art recommendation algorithms in evolving networks. We find that the recommendation accuracy in general decreases with time if the evolution of the online network fully depends on the recommendation. Interestingly, some randomness in users' choice can significantly improve the long-term accuracy of the recommendation algorithm. When a hybrid recommendation algorithm is applied, we find that the optimal parameter gradually shifts towards the diversity-favoring recommendation algorithm, indicating that recommendation diversity is essential to keep a high long-term recommendation accuracy. Finally, we confirm our conclusions by studying the recommendation on networks with the real evolution data.

  10. The evolving defense communications system

    NASA Astrophysics Data System (ADS)

    Testa, Ann M.; Jones, Walter I.

    1992-05-01

    Command, control, and communications (C3) systems 'help lift the fog of war that adds uncertainty to any military operation.' They multiply the effectiveness of weapon systems and are critical components of our nation's warfighting capability. One of these critical systems is the Defense Communications System (DCS) which evolved over the past 30 years. Several factors drove this evolution, including constrained budgets, the need to improve the effectiveness and efficiency of the service provided, compatibility and interoperability, and technological advances. Based on lessons learned from Desert Shield/Desert Storm and the changing environment, force structure, and strategy, it is time to advance the DCS to its next stage. The future DCS must be flexible enough to adapt to any situation anywhere in the world. Mobile, modular building block packages of communications equipment must be available to provide effective communications capability to deployed units immediately upon arrival. Total integration and interoperability among military, commercial, and other government agencies' communication systems is a must if survivable, robust connectivity is going to be available when needed. Integration planning must begin now.

  11. Multiscale modelling of evolving foams

    NASA Astrophysics Data System (ADS)

    Saye, R. I.; Sethian, J. A.

    2016-06-01

    We present a set of multi-scale interlinked algorithms to model the dynamics of evolving foams. These algorithms couple the key effects of macroscopic bubble rearrangement, thin film drainage, and membrane rupture. For each of the mechanisms, we construct consistent and accurate algorithms, and couple them together to work across the wide range of space and time scales that occur in foam dynamics. These algorithms include second order finite difference projection methods for computing incompressible fluid flow on the macroscale, second order finite element methods to solve thin film drainage equations in the lamellae and Plateau borders, multiphase Voronoi Implicit Interface Methods to track interconnected membrane boundaries and capture topological changes, and Lagrangian particle methods for conservative liquid redistribution during rearrangement and rupture. We derive a full set of numerical approximations that are coupled via interface jump conditions and flux boundary conditions, and show convergence for the individual mechanisms. We demonstrate our approach by computing a variety of foam dynamics, including coupled evolution of three-dimensional bubble clusters attached to an anchored membrane and collapse of a foam cluster.

  12. Attack resilience of the evolving scientific collaboration network.

    PubMed

    Liu, Xiao Fan; Xu, Xiao-Ke; Small, Michael; Tse, Chi K

    2011-01-01

    Stationary complex networks have been extensively studied in the last ten years. However, many natural systems are known to be continuously evolving at the local ("microscopic") level. Understanding the response to targeted attacks of an evolving network may shed light on both how to design robust systems and finding effective attack strategies. In this paper we study empirically the response to targeted attacks of the scientific collaboration networks. First we show that scientific collaboration network is a complex system which evolves intensively at the local level--fewer than 20% of scientific collaborations last more than one year. Then, we investigate the impact of the sudden death of eminent scientists on the evolution of the collaboration networks of their former collaborators. We observe in particular that the sudden death, which is equivalent to the removal of the center of the egocentric network of the eminent scientist, does not affect the topological evolution of the residual network. Nonetheless, removal of the eminent hub node is exactly the strategy one would adopt for an effective targeted attack on a stationary network. Hence, we use this evolving collaboration network as an experimental model for attack on an evolving complex network. We find that such attacks are ineffectual, and infer that the scientific collaboration network is the trace of knowledge propagation on a larger underlying social network. The redundancy of the underlying structure in fact acts as a protection mechanism against such network attacks.

  13. A slowly evolving host moves first in symbiotic interactions

    NASA Astrophysics Data System (ADS)

    Damore, James; Gore, Jeff

    2011-03-01

    Symbiotic relationships, both parasitic and mutualistic, are ubiquitous in nature. Understanding how these symbioses evolve, from bacteria and their phages to humans and our gut microflora, is crucial in understanding how life operates. Often, symbioses consist of a slowly evolving host species with each host only interacting with its own sub-population of symbionts. The Red Queen hypothesis describes coevolutionary relationships as constant arms races with each species rushing to evolve an advantage over the other, suggesting that faster evolution is favored. Here, we use a simple game theoretic model of host- symbiont coevolution that includes population structure to show that if the symbionts evolve much faster than the host, the equilibrium distribution is the same as it would be if it were a sequential game where the host moves first against its symbionts. For the slowly evolving host, this will prove to be advantageous in mutualisms and a handicap in antagonisms. The model allows for symbiont adaptation to its host, a result that is robust to changes in the parameters and generalizes to continuous and multiplayer games. Our findings provide insight into a wide range of symbiotic phenomena and help to unify the field of coevolutionary theory.

  14. Breeding without breeding: is a complete pedigree necessary for efficient breeding?

    PubMed

    El-Kassaby, Yousry A; Cappa, Eduardo P; Liewlaksaneeyanawin, Cherdsak; Klápště, Jaroslav; Lstibůrek, Milan

    2011-01-01

    Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called "Breeding without Breeding" (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB.

  15. Capital and income breeding traits differentiate trophic match–mismatch dynamics in large herbivores

    PubMed Central

    Kerby, Jeffrey; Post, Eric

    2013-01-01

    For some species, climate change has altered environmental conditions away from those in which life-history strategies evolved. In such cases, if adaptation does not keep pace with these changes, existing life-history strategies may become maladaptive and lead to population declines. We use life-history theory, with a specific emphasis on breeding strategies, in the context of the trophic match–mismatch framework to form generalizable hypotheses about population-level consumer responses to climate-driven perturbations in resource availability. We first characterize the income and breeding traits of sympatric caribou and muskoxen populations in western Greenland, and then test trait-based hypotheses about the expected reproductive performance of each population during a period of high resource variability at that site. The immediate reproductive performance of income breeding caribou decreased with trophic mismatch. In contrast, capital breeding muskoxen were relatively unaffected by current breeding season resource variability, but their reproductive performance was sensitive to resource conditions from previous years. These responses matched our expectations about how capital and income breeding strategies should influence population susceptibility to phenological mismatch. We argue for a taxon-independent assessment of trophic mismatch vulnerability based on a life-history strategy perspective in the context of prevailing environmental conditions. PMID:23836789

  16. Traditional and modern plant breeding methods with examples in rice (Oryza sativa L.).

    PubMed

    Breseghello, Flavio; Coelho, Alexandre Siqueira Guedes

    2013-09-04

    Plant breeding can be broadly defined as alterations caused in plants as a result of their use by humans, ranging from unintentional changes resulting from the advent of agriculture to the application of molecular tools for precision breeding. The vast diversity of breeding methods can be simplified into three categories: (i) plant breeding based on observed variation by selection of plants based on natural variants appearing in nature or within traditional varieties; (ii) plant breeding based on controlled mating by selection of plants presenting recombination of desirable genes from different parents; and (iii) plant breeding based on monitored recombination by selection of specific genes or marker profiles, using molecular tools for tracking within-genome variation. The continuous application of traditional breeding methods in a given species could lead to the narrowing of the gene pool from which cultivars are drawn, rendering crops vulnerable to biotic and abiotic stresses and hampering future progress. Several methods have been devised for introducing exotic variation into elite germplasm without undesirable effects. Cases in rice are given to illustrate the potential and limitations of different breeding approaches.

  17. 50 CFR 23.46 - What are the requirements for registering a commercial breeding operation for Appendix-I wildlife...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a commercial breeding operation for Appendix-I wildlife and commercially exporting specimens? 23.46... WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES OF WILD FAUNA AND... registering a commercial breeding operation for Appendix-I wildlife and commercially exporting specimens? (a...

  18. Submillimeter observations of evolved stars

    SciTech Connect

    Sopka, R.J.; Hildebrand, R.; Jaffe, D.T.; Gatley, I.; Roellig, T.; Werner, M.; Jura, M.; Zuckerman, B.

    1985-07-01

    Broad-band submillimeter observations of the thermal emission from evolved stars have been obtained with the United Kingdom Infrared Telescope on Mauna Kea, Hawaii. These observations, at an effective wavelength of 400 ..mu..m, provide the most direct method for estimating the mass loss rate in dust from these stars and also help to define the long-wavelength thermal spectrum of the dust envelopes. The mass loss rates in dust that we derive range from 10/sup -9/ to 10/sup -6/ M/sub sun/ yr/sup -1/ and are compared with mass loss rates derived from molecular line observations to estimate gas-to-dust ratios in outflowing envelopes. These values are found to be generally compatible with the interstellar gas-to-dust ratio of approx.100 if submillimeter emissivities appropriate to amorphous grain structures are assumed. Our analysis of the spectrum of IRC+10216 confirms previous suggestions that the grain emissivity varies as lambda/sup -1.2/ rather than as lambda/sup -2/ for 10

  19. Voyages Through Time: Everything Evolves

    NASA Astrophysics Data System (ADS)

    Pendleton, Y. J.; Tarter, J. C.; DeVore, E. K.; O'Sullivan, K. A.; Taylor, S. M.

    2001-12-01

    Evolutionary change is a powerful framework for studying our world and our place therein. It is a recurring theme in every realm of science: over time, the universe, the planet Earth, life, and human technologies all change, albeit on vastly different scales. Evolution offers scientific explanations for the age-old question, "Where did we come from?" In addition, historical perspectives of science show how our understanding has evolved over time. The complexities of all of these systems will never reveal a "finished" story. But it is a story of epic size, capable of inspiring awe and of expanding our sense of time and place, and eminently worthy of investigating. This story is the basis of Voyages Through Time. Voyages Through Time (VTT), provides teachers with not only background science content and pedagogy, but also with materials and resources for the teaching of evolution. The six modules, Cosmic Evolution, Planetary Evolution, Origin of Life, Evolution of Life, Hominid Evolution, and Evolution of Technology, emphasize student inquiry, and promote the nature of science, as recommended in the NSES and BSL. The modules are unified by the overarching theme of evolution and the meta questions: "What is changing?" "What is the rate of change?" and "What is the mechanism of change?" Determination of student outcomes for the project required effective collaboration of scientists, teachers, students and media specialists. The broadest curricula students outcomes are 1) an enjoyment of science, 2) an understanding of the nature of science, especially the understanding of evidence and re-evaluation, and 3) key science content. The curriculum is being developed by the SETI Institute, NASA Ames Research Center, California Academy of Sciences, and San Francisco State University, and is funded by the NSF (IMD 9730693), with support form Hewlett-Packard Company, The Foundation for Microbiology, Combined Federated Charities, NASA Astrobiology Institute, and NASA Fundamental

  20. Finding Aedes aegypti in a natural breeding site in an urban zone, Sao Paulo, Southeastern Brazil

    PubMed Central

    Lima-Camara, Tamara Nunes; Urbinatti, Paulo Roberto; Chiaravalloti-Neto, Francisco

    2016-01-01

    ABSTRACT This is the description of how nine Aedes aegypti larvae were found in a natural breeding site in the Pinheiros neighborhood, city of Sao Paulo, SP, Southeastern Brazil. The record was conducted in December 2014, during an entomological surveillance program of dengue virus vectors, with an active search of potential breeding sites, either artificial or natural. Finding Ae. aegypti larvae in a tree hole shows this species’ ability to use both artificial and natural environments as breeding sites and habitats, which points towards the importance of maintaining continuous surveillance on this mosquito in all kinds of water-holding containers. PMID:26982959

  1. Evolving fuzzy rules in a learning classifier system

    NASA Technical Reports Server (NTRS)

    Valenzuela-Rendon, Manuel

    1993-01-01

    The fuzzy classifier system (FCS) combines the ideas of fuzzy logic controllers (FLC's) and learning classifier systems (LCS's). It brings together the expressive powers of fuzzy logic as it has been applied in fuzzy controllers to express relations between continuous variables, and the ability of LCS's to evolve co-adapted sets of rules. The goal of the FCS is to develop a rule-based system capable of learning in a reinforcement regime, and that can potentially be used for process control.

  2. The Evolving Nature of Hepatic Abscess: A Review

    PubMed Central

    Mavilia, Marianna G.; Molina, Marco; Wu, George Y.

    2016-01-01

    Abstract Hepatic abscess (HA) remains a serious and often difficult to diagnose problem. HAs can be divided into three main categories based on the underlying conditions: infectious, malignant, and iatrogenic. Infectious abscesses include those secondary to direct extension from local infection, systemic bacteremia, and intra-abdominal infections that seed the portal system. However, over the years, the etiologies and risks factors for HA have continued to evolve. Prompt recognition is important for instituting effective management and obtaining good outcomes. PMID:27350946

  3. The Evolving Nature of Hepatic Abscess: A Review.

    PubMed

    Mavilia, Marianna G; Molina, Marco; Wu, George Y

    2016-06-28

    Hepatic abscess (HA) remains a serious and often difficult to diagnose problem. HAs can be divided into three main categories based on the underlying conditions: infectious, malignant, and iatrogenic. Infectious abscesses include those secondary to direct extension from local infection, systemic bacteremia, and intra-abdominal infections that seed the portal system. However, over the years, the etiologies and risks factors for HA have continued to evolve. Prompt recognition is important for instituting effective management and obtaining good outcomes.

  4. Cassini Radar at Titan : Evolving Studies of an Evolving World

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.

    2013-04-01

    The Cassini RADAR investigation continues to explore Titan : here I summarize some recent and ongoing developments. Geological interpretation of SAR imaging engages a wide community, in particular addressing Titan's dunes, lakes, seas and fluvial systems, impact craters and possible cryovolcanic features. Mapping of these features continues to suggest a dynamic world, with geologically-recent surface change due to tectonic, hydrological and aeolian processes. Mapping of fluvial channels and shoreline features suggests some tectonic controls and spatially-variable land/sea level changes. A despeckle filter applied to the images has proven popular for image interpretation, for example in resolving what may be star- and barchanoid dune morphologies which contrast with the dominant linear type. New observations in 2012 (T83, T84 and T86) place bounds on liquid accumulation in the northern polar regions - not expected to be substantial for another couple of years - and have highlighted a possibly cryomagma-inflated 'hot cross bun' feature and anomalous midlatitude ridges that may be paleodunes from a different climate epoch. The accumulating body of topographic data from altimetry and SARtopo has permitted the assembly of a global topographic map (albeit substantially interpolated) and an estimate of the spherical harmonic shape out to degree ~12. These datasets will be of substantial value in interpreting Titan's structure and geology, and as a boundary condition on global circulation models and fluvial studies. The growing number of overlap regions also permits stereo topography on smaller scales (e.g. of impact structures Ksa and Soi) which helps to understand the processes obliterating craters on Titan.

  5. Evolving evolutionary algorithms using linear genetic programming.

    PubMed

    Oltean, Mihai

    2005-01-01

    A new model for evolving Evolutionary Algorithms is proposed in this paper. The model is based on the Linear Genetic Programming (LGP) technique. Every LGP chromosome encodes an EA which is used for solving a particular problem. Several Evolutionary Algorithms for function optimization, the Traveling Salesman Problem and the Quadratic Assignment Problem are evolved by using the considered model. Numerical experiments show that the evolved Evolutionary Algorithms perform similarly and sometimes even better than standard approaches for several well-known benchmarking problems.

  6. Acquiring Evolving Technologies: Web Services Standards

    DTIC Science & Technology

    2016-06-30

    2006 Carnegie Mellon University Acquiring Evolving Technologies : Web Services Standards Harry L. Levinson Software Engineering Institute Carnegie...Acquiring Evolving Technologies : Web Services Standards 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 Acquiring Evolving Technologies : Web Services Standards © 2006 Carnegie Mellon University Acquiring

  7. Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle.

    PubMed

    Hennicke, Janos C; James, David J; Weimerskirch, Henri

    2015-01-01

    In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi) were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas) allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.

  8. Consensus in evolving networks of mobile agents

    NASA Astrophysics Data System (ADS)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-02-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving networks defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this talk can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  9. Women's oral health: the evolving science.

    PubMed

    Sinkford, Jeanne C; Valachovic, Richard W; Harrison, Sonja G

    2008-02-01

    The evidence base for women's oral health is emerging from legislative action, clinical research, and survey documentation. The Women's Health in the Dental School Curriculum study (1999) followed a similar study (1996) of medical school curricula. Both of these major efforts resulted from statutory mandates in the National Institutes of Health Revitalization Act of 1993 (updated October 2000). A major study of the Institute of Medicine (IOM) National Academy of Sciences in 2001 concluded that "the study of sex differences is evolving into a mature science." This IOM study documented the scientific basis for gender-related policy and research and challenged the dental research enterprise to conduct collaborative, cross-disciplinary research on gender-related issues in oral health, disease, and disparities. This report chronicles some of the factors that have and continue to influence concepts of women's oral health in dental education, research, and practice. Gender issues related to women's health are no longer restricted to reproductive issues but are being considered across the life span and include psychosocial factors that impact women's health and treatment outcomes.

  10. Evolving role of pediatric nurse practitioners.

    PubMed

    Aruda, Mary M; Griffin, Valerie J; Schartz, Kathryn; Geist, Melissa

    2016-02-01

    To report and interpret findings from national pediatric nurse practitioner (PNP) job analysis surveys reflecting the changes in the knowledge and skills required for advanced practice. National role delineation studies (RDS) conducted by American Nurses Credentialing Center (ANCC) in 2003, 2008, and 2011. Since the first nurse practitioner (NP) program was established in 1965 to train pediatric nurses for advanced practice, the role of the PNP has continued to develop. The RDS results demonstrate the increased autonomy of PNP's prescription of medication as the top work activity category identified, followed by the reporting of suspected abuse, exploitation, and/or neglect and immunizing based on current recommendations. Analysis of the changes in role or work activities, tied to the knowledge and skills required to perform those activities, can provide content for educators updating curriculum, for clinicians to remain current in their practice and impact healthcare policy. The current PNP role has evolved to meet the workforce demands of providing primary care to the pediatric population with increasing complex social and healthcare needs. Role analysis is important as NPs move forward to practice to the full extent of their education and training. ©2015 American Association of Nurse Practitioners.

  11. Evolving Resistance Among Gram-positive Pathogens

    PubMed Central

    Munita, Jose M.; Bayer, Arnold S.; Arias, Cesar A.

    2015-01-01

    Antimicrobial therapy is a key component of modern medical practice and a cornerstone for the development of complex clinical interventions in critically ill patients. Unfortunately, the increasing problem of antimicrobial resistance is now recognized as a major public health threat jeopardizing the care of thousands of patients worldwide. Gram-positive pathogens exhibit an immense genetic repertoire to adapt and develop resistance to virtually all antimicrobials clinically available. As more molecules become available to treat resistant gram-positive infections, resistance emerges as an evolutionary response. Thus, antimicrobial resistance has to be envisaged as an evolving phenomenon that demands constant surveillance and continuous efforts to identify emerging mechanisms of resistance to optimize the use of antibiotics and create strategies to circumvent this problem. Here, we will provide a broad perspective on the clinical aspects of antibiotic resistance in relevant gram-positive pathogens with emphasis on the mechanistic strategies used by these organisms to avoid being killed by commonly used antimicrobial agents. PMID:26316558

  12. Family living sets the stage for cooperative breeding and ecological resilience in birds

    PubMed Central

    Drobniak, Szymon M.; Nakagawa, Shinichi; Botero, Carlos A.

    2017-01-01

    Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent–offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that favor the evolution of cooperative breeding can be confounded if this process is not considered to include 2 steps. Specifically, phylogenetic linear mixed models show that the formation of families was associated with more productive and seasonal environments, where prolonged parent–offspring associations are likely to be less costly. However, our data show that the subsequent evolution of cooperative breeding was instead linked to environments with variable productivity, where helpers at the nest can buffer reproductive failure in harsh years. The proposed 2-step framework helps resolve current disagreements about the role of environmental forces in the evolution of cooperative breeding and better explains the geographic distribution of this trait. Many geographic hotspots of cooperative breeding have experienced a historical decline in productivity, suggesting that a higher proportion of family-living species could have been able to avoid extinction under harshening conditions through the evolution of cooperative breeding. These findings underscore the importance of considering the potentially different factors that drive different steps in the evolution of complex adaptations. PMID:28636615

  13. The Evolving Defense Industrial Base

    DTIC Science & Technology

    2007-05-16

    Base May 16, 2007 9 • Industry Is Focused on the Long Term – Earn a profit that exceeds the cost of capital – Corporate Value is Created through...VFW Fokker Dornier AISA Racal MBB …And the Same Industrial Consolidation has Taken Place in Europe 5 Rapid consolidation of core US sectors continues...Acquisition Landscape Year # Targets Acquired $ Value 2003 21 $2.7B 2004 19 $3.0B 2005 31 $7.4B Total 71 $13.2B Net Effect: Increased Global Teaming on

  14. Water in evolved lunar rocks

    NASA Astrophysics Data System (ADS)

    Robinson, Katharine Lynn

    The Moon was thought to be completely anhydrous until indigenous water was found in lunar samples in 2008. This discovery raised two fundamental questions about the Moon: how much water is present in the bulk Moon and is water uniformly distributed in the lunar interior? To address these questions, I studied a suite of lunar samples rich in a chemical component called KREEP (K, Rare Earth Elements, P), all of which are incompatible elements. Water behaves as an incompatible element in magmas, so KREEP-rich lunar samples are potentially water rich. In this dissertation, I present the results of a petrologic study of KREEP-rich lunar rocks, measurements of their water contents and deuterium (D) to hydrogen (H) ratios (D/H), and examined where these rocks fit into our understanding of water in the Moon as a whole. We performed a study of highly evolved, KREEP-rich lunar rocks called felsites and determined that they contain quartz. Using cooling rates derived from quartz-Ti thermometry, we show the felsites originated at a minimum pressure of ˜1 kbar, corresponding to a minimum depth of 20-25 km in the lunar crust. We calculate that at that pressure water would have been soluble in the melt, indicating that degassing of H2O from the felsite parental melts was likely minimal and hydrogen isotopes in intrusive rocks are likely unfractionated. We then measured D/H in apatite in KREEP-rich intrusive rocks to clarify the solar system source of the Moon's water. When viewed in the context of other lunar D/H studies, our results indicate there are at least three distinctive reservoirs in the lunar interior, including an ultra-low D reservoir that could represent a primitive component in the Moon's interior. Furthermore, our measurements of residual glass in a KREEP basalt show that the KREEP basaltic magmas contained 10 times less water than the source of the Apollo 17 pyroclastic glass beads, indicating that, though wetter than previously thought, the concentration of

  15. [Progress and countermeasures of Dendrobium officinale breeding].

    PubMed

    Si, Jin-Ping; He, Bo-wei; Yu, Qiao-xian

    2013-02-01

    The standandized cultivation of Chinese medicinal materials is based on variety. With the rapid development of Dendrobium officinale industry and increasing demand of improved varieties, many studies have concentrated on the variety breeding of D. officinale and subsequently achieved remarkable success. This paper systematically expounds the research progress of D. officinale breeding, e. g. the collection and differentiated evaluation for germplasm, theory and practice for variety breeding, tissue culture and efficient production with low-carbon for germchit, and DNA molecular marker-assisted breeding, and then indicates the main problems of the current breeding of D. officinale. Furthermore, the priorities and keys for the further breeding of D. officinale have been pointed out.

  16. Reference genome of wild goat (capra aegagrus) and sequencing of goat breeds provide insight into genic basis of goat domestication.

    PubMed

    Dong, Yang; Zhang, Xiaolei; Xie, Min; Arefnezhad, Babak; Wang, Zongji; Wang, Wenliang; Feng, Shaohong; Huang, Guodong; Guan, Rui; Shen, Wenjing; Bunch, Rowan; McCulloch, Russell; Li, Qiye; Li, Bo; Zhang, Guojie; Xu, Xun; Kijas, James W; Salekdeh, Ghasem Hosseini; Wang, Wen; Jiang, Yu

    2015-06-05

    Domestic goats (Capra hircus) have been selected to play an essential role in agricultural production systems, since being domesticated from their wild progenitor, bezoar (Capra aegagrus). A detailed understanding of the genetic consequences imparted by the domestication process remains a key goal of evolutionary genomics. We constructed the reference genome of bezoar and sequenced representative breeds of domestic goats to search for genomic changes that likely have accompanied goat domestication and breed formation. Thirteen copy number variation genes associated with coat color were identified in domestic goats, among which ASIP gene duplication contributes to the generation of light coat-color phenotype in domestic goats. Analysis of rapidly evolving genes identified genic changes underlying behavior-related traits, immune response and production-related traits. Based on the comparison studies of copy number variation genes and rapidly evolving genes between wild and domestic goat, our findings and methodology shed light on the genetic mechanism of animal domestication and will facilitate future goat breeding.

  17. [Pain caused by breeding in dogs].

    PubMed

    Reetz, I C

    1997-02-01

    According to German animal protection law it is not aloud to breed animals if it has to be expected that the offspring will suffer pain caused by hereditary characters. This paper deals with those hereditary defects which are used directly or indirectly (because of linkage to other desirable traits) in dog breeding. By the patho-physiological symptoms and the genetics of selected hereditary defects recommendations are exemplified how these defects should be handled in breeding that pain can be avoided.

  18. Molecular tools for breeding basidiomycetes.

    PubMed

    Ramírez, L; Larraya, L M; Pisabarro, A G

    2000-09-01

    The industrial production of edible basidiomycetes is increasing every year as a response to the increasing public demand of them because of their nutritional properties. About a dozen of fungal species can be currently produced for food with sound industrial and economic bases. Notwithstanding, this production is threatened by biotic and abiotic factors that make it necessary to improve the fungal strains currently used in industry. Breeding of edible basidiomycetes, however, has been mainly empirical and slow since the genetic tools useful in the selection of the new genetic material to be introduced in the commercial strains have not been developed for these fungi as it was for other organisms. In this review we will discuss the main genetic factors that should be considered to develop breeding approaches and tools for higher basidiomycetes. These factors are (i) the genetic system controlling fungal mating; (ii) the genomic structure and organisation of these fungi; and (iii) the identification of genes involved in the control of quantitative traits. We will discuss the weight of these factors using the oyster mushroom Pleurotus ostreatus as a model organism for most of the edible fungi cultivated industrially.

  19. [New technology in maize breeding].

    PubMed

    Konstantinov, K; Mladenović, S; Stojkov, S; Delić, N; Gosić, S; Petrović, R; Lević, J; Denić, M

    1992-01-01

    Results obtained by several approaches in the application of Biotechnology in maize breeding are reviewed. RFLP technology in the determination of genetic variation; gene transfer by the use of different methods of gene delivery and the determination of gene integration. Three technologies for foreign gene introduction have been applied; injection of plasmid pRT100 neo into archesporial tissue before micro and macro sporogenesis, slightly modified pollen-tube pathway technology and dry seed incubation in plasmid DNA solution. NPTII gene integration was followed by dot-blot and Southern blot analysis of plant DNA of both T1 and T2 plants. Gene expression was analysed by neomycin phosphotransferase activity. Transformed plants contained the selective NPTII gene sequence in an active form. Bacterial gene integration induced several heritable changes of plant phenotype. As an important change, alteration of the flowering time has been used as a criterion for selection and plant propagation to keep transformed progeny. Besides plant genome transformation, endogenous bacteria living in different maize tissue were found. As a perspective approach for biotechnology application in maize breeding biological vaccine construction has been selected. Therefore, antagonistic effect of gram positive bacterial strains to several pathogenic fungi was investigated. Results obtained after in vivo experiments are discussed.

  20. The breeding bird survey, 1966

    USGS Publications Warehouse

    Robbins, Chandler S.; Van Velzen, Willet T.

    1967-01-01

    A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

  1. The Breeding Bird Survey, 1966

    USGS Publications Warehouse

    Robbins, C.S.; Van Velzen, W.T.

    1967-01-01

    A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

  2. Breeding without Breeding: Is a Complete Pedigree Necessary for Efficient Breeding?

    PubMed Central

    El-Kassaby, Yousry A.; Cappa, Eduardo P.; Liewlaksaneeyanawin, Cherdsak; Klápště, Jaroslav; Lstibůrek, Milan

    2011-01-01

    Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called “Breeding without Breeding” (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB. PMID:21991342

  3. Genomics-assisted breeding in fruit trees

    PubMed Central

    Iwata, Hiroyoshi; Minamikawa, Mai F.; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding. PMID:27069395

  4. Differentiation among Spanish sheep breeds using microsatellites

    PubMed Central

    Arranz, Juan-José; Bayón, Yolanda; Primitivo, Fermín San

    2001-01-01

    Genetic variability at 18 microsatellites was analysed on the basis of individual genotypes in five Spanish breeds of sheep – Churra, Latxa, Castellana, Rasa-Aragonesa and Merino -, with Awassi also being studied as a reference breed. The degree of population subdivision calculated between Spanish breeds from FST diversity indices was around 7% of total variability. A high degree of reliability was obtained for individual-breed assignment from the 18 loci by using different approaches among which the Bayesian method provided to be the most efficient, with an accuracy for nine microsatellites of over 99%. Analysis of the Bayesian assignment criterion illustrated the divergence between any one breed and the others, which was highest for Awassi sheep, while no great differences were evident among the Spanish breeds. Relationships between individuals were analysed from the proportion of shared alleles. The resulting dendrogram showed a remarkable breed structure, with the highest level of clustering among members of the Spanish breeds in Latxa and the lowest in Merino sheep, the latter breed exhibiting a peculiar pattern of clustering, with animals grouped into several closely set nodes. Analysis of individual genotypes provided valuable information for understanding intra- and inter-population genetic differences and allowed for a discussion with previously reported results using populations as taxonomic units. PMID:11712973

  5. Fish genome manipulation and directional breeding.

    PubMed

    Ye, Ding; Zhu, ZuoYan; Sun, YongHua

    2015-02-01

    Aquaculture is one of the fastest developing agricultural industries worldwide. One of the most important factors for sustainable aquaculture is the development of high performing culture strains. Genome manipulation offers a powerful method to achieve rapid and directional breeding in fish. We review the history of fish breeding methods based on classical genome manipulation, including polyploidy breeding and nuclear transfer. Then, we discuss the advances and applications of fish directional breeding based on transgenic technology and recently developed genome editing technologies. These methods offer increased efficiency, precision and predictability in genetic improvement over traditional methods.

  6. Chemical classification of cattle. 1. Breed groups.

    PubMed

    Baker, C M; Manwell, C

    1980-01-01

    From approximately 1000 papers with data on protein polymorphism in some 216 breeds of cattle, 10 polymorphic proteins were compared in means and variances of gene frequencies (arcsin p 1/2) for ten well-recognized breed groups for 196 of the breeds. The polymorphic proteins were alpha-lactalbumin, beta-lactoglobulin, caseins (alpha s1, beta and chi), serum albumin, transferrin, haemoglobin, amylase I and carbonic anhydrase II. The breed groups were North European, Pied Lowland, European Red brachyceros, Channel Island brachyceros, Upland brachyceros, primigenius-brachyceros mixed, primigenius, Indian Zebu, African Humped (with Zebu admixture), and African Humped (Sanga). The coherence within groups and the differences between groups are often impressive. Only carbonic anhydrase II fails to differentiate at least some of the major breed groups. In some cases paradoxical distributions of rare genetic variants can be explained by a more detailed inspection of breed history. The chemical data support the morphological and geographical divisions of cattle into major breed groups. There are three distinct but related brachyceros groups; for some polymorphisms the two Channel Island breeds, the Jersey and the Guernsey, are quite divergent. Although some authorities have considered the Pied Lowland as primigenius, it is a very distinct breed group.

  7. Genomics-assisted breeding in fruit trees.

    PubMed

    Iwata, Hiroyoshi; Minamikawa, Mai F; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding.

  8. Implementation of Genomic Prediction in Lolium perenne (L.) Breeding Populations

    PubMed Central

    Grinberg, Nastasiya F.; Lovatt, Alan; Hegarty, Matt; Lovatt, Andi; Skøt, Kirsten P.; Kelly, Rhys; Blackmore, Tina; Thorogood, Danny; King, Ross D.; Armstead, Ian; Powell, Wayne; Skøt, Leif

    2016-01-01

    Perennial ryegrass (Lolium perenne L.) is one of the most widely grown forage grasses in temperate agriculture. In order to maintain and increase its usage as forage in livestock agriculture, there is a continued need for improvement in biomass yield, quality, disease resistance, and seed yield. Genetic gain for traits such as biomass yield has been relatively modest. This has been attributed to its long breeding cycle, and the necessity to use population based breeding methods. Thanks to recent advances in genotyping techniques there is increasing interest in genomic selection from which genomically estimated breeding values are derived. In this paper we compare the classical RRBLUP model with state-of-the-art machine learning techniques that should yield themselves easily to use in GS and demonstrate their application to predicting quantitative traits in a breeding population of L. perenne. Prediction accuracies varied from 0 to 0.59 depending on trait, prediction model and composition of the training population. The BLUP model produced the highest prediction accuracies for most traits and training populations. Forage quality traits had the highest accuracies compared to yield related traits. There appeared to be no clear pattern to the effect of the training population composition on the prediction accuracies. The heritability of the forage quality traits was generally higher than for the yield related traits, and could partly explain the difference in accuracy. Some population structure was evident in the breeding populations, and probably contributed to the varying effects of training population on the predictions. The average linkage disequilibrium between adjacent markers ranged from 0.121 to 0.215. Higher marker density and larger training population closely related with the test population are likely to improve the prediction accuracy. PMID:26904088

  9. Recovery of breeding success in a population of brown pelicans

    USGS Publications Warehouse

    Mendenhall, V.M.; Prouty, R.M.

    1978-01-01

    Breeding populations of the brown pelican (Pelecanus occidentalis) declined during the 1960's on both east and west coasts of the United States. In 1969, colonies in South Carolina fledged an average of 0.78 young per nest, and those in California only 0.004. The minimum production for population stability has been estimated to be 1.0 to 1.2 fledglings per nest. The South Carolina population may have decreased by as much as 80% during the previous decade. Organochlorine pesticides were implicated as a cause of population decline. Eggs from South Carolina contained an average of 5.4 parts per million (ppm) of DDE (wet weight basis) in 1969, and those from California about 70 ppm wet weight. Shells of South Carolina brown pelican eggs were,17% thinner than normal, and those from California were 30% thinner, compared with shells of eggs laid before DDE was introduced in 1947; crushed eggs were common in the colonies. DDE was the primary cause of shell thinning, but dieldrin was also associated with breeding failure, and both may be embryotoxic. Brown pelicans also declined in Louisiana and Texas during this period, in association with shell thinning and relatively high organochlorine levels. Eggs of pelicans in Florida, however, contained lower residues, and numbers have remained stable. In 1969, the Patuxent Wildlife Research Center and Cape Romain National Wildlife Refuge initiated an intensive study of the South Carolina population. Size of the breeding colonies, production, eggshell thickness, and organochlorine residues were monitored each year. Between 1969 and 1976 organochlorines in the eggs declined gradually, reproductive success improved, and the breeding population doubled. We have continued to monitor the South Carolina brown pelican population. Results for 1977 and 1978 are presented here, with an evaluation of the significance and possible causes of current breeding success.

  10. Does food supplementation really enhance productivity of breeding birds?

    PubMed

    Harrison, Timothy J E; Smith, Jennifer A; Martin, Graham R; Chamberlain, Dan E; Bearhop, Stuart; Robb, Gillian N; Reynolds, S James

    2010-10-01

    Food availability influences multiple stages of the breeding cycle of birds, and supplementary feeding has helped in its understanding. Most supplementation studies have reported advancements of laying, whilst others, albeit less numerous, have also demonstrated fitness benefits such as larger clutches, shorter incubation periods, and greater hatching success. Relatively few studies, however, have investigated the effects of supplementary feeding for protracted periods across multiple stages of the breeding cycle. These effects are important to understand since long-term food supplementation of birds is recommended in urban habitats and is used as a tool to increase reproductive output in endangered species. Here, we compare the breeding phenology and productivity of blue tits Cyanistes caeruleus and great tits Parus major breeding in food-supplemented and non-supplemented blocks in a broadleaf woodland in central England over three seasons (2006-2008). Supplementation was provided continuously from several weeks pre-laying until hatching, and had multiple significant effects. Most notably, supplementation reduced brood size significantly in both species, by half a chick or more at hatching (after controlling for year and hatching date). Reduced brood sizes in supplemented pairs were driven by significantly smaller clutches in both species and, in blue tits, significantly lower hatching success. These are novel and concerning findings of food supplementation. As expected, supplementary feeding advanced laying and shortened incubation periods significantly in both species. We discuss the striking parallels between our findings and patterns in blue and great tit reproduction in urban habitats, and conclude that supplementary feeding may not always enhance the breeding productivity of birds.

  11. Genomic-based-breeding tools for tropical maize improvement.

    PubMed

    Chakradhar, Thammineni; Hindu, Vemuri; Reddy, Palakolanu Sudhakar

    2017-09-05

    Maize has traditionally been the main staple diet in the Southern Asia and Sub-Saharan Africa and widely grown by millions of resource poor small scale farmers. Approximately, 35.4 million hectares are sown to tropical maize, constituting around 59% of the developing worlds. Tropical maize encounters tremendous challenges besides poor agro-climatic situations with average yields recorded <3 tones/hectare that is far less than the average of developed countries. On the contrary to poor yields, the demand for maize as food, feed, and fuel is continuously increasing in these regions. Heterosis breeding introduced in early 90 s improved maize yields significantly, but genetic gains is still a mirage, particularly for crop growing under marginal environments. Application of molecular markers has accelerated the pace of maize breeding to some extent. The availability of array of sequencing and genotyping technologies offers unrivalled service to improve precision in maize-breeding programs through modern approaches such as genomic selection, genome-wide association studies, bulk segregant analysis-based sequencing approaches, etc. Superior alleles underlying complex traits can easily be identified and introgressed efficiently using these sequence-based approaches. Integration of genomic tools and techniques with advanced genetic resources such as nested association mapping and backcross nested association mapping could certainly address the genetic issues in maize improvement programs in developing countries. Huge diversity in tropical maize and its inherent capacity for doubled haploid technology offers advantage to apply the next generation genomic tools for accelerating production in marginal environments of tropical and subtropical world. Precision in phenotyping is the key for success of any molecular-breeding approach. This article reviews genomic technologies and their application to improve agronomic traits in tropical maize breeding has been reviewed in

  12. Whirling System of Water Exchange in Breeding Pools

    NASA Astrophysics Data System (ADS)

    Matej, Karolina; Pawliczka, Iwona; Sawicki, Jerzy M.; Wielgat, Paweł; Zima, Piotr

    2016-12-01

    To create proper living conditions for sea mammals kept in closed systems, one has to make sure that the characteristics of breeding pools, such as their shape, dimensions, the facing of the walls and bottom, as well as the quality and motion of water, resemble as closely as possible the natural environment of the animals. An appropriate system of water exchange plays a very important role here. A complete exchange of water is time-consuming, expensive and troublesome, so it can be performed only periodically and should be supported by a supplementary continuous exchange. This operation improves water quality and can create a proper velocity field in breeding pools. The breeding pools investigated in the present study are located in a sealarium in Hel (Poland), which belongs to the Institute of Oceanography of the Gdansk University. Tracer measurements, carried out in these reservoirs made it possible to evaluate the intensity of continuous water exchange. It was found that this intensity was insufficient (as evidenced by large dead zones in the pools and short detention time), and therefore alterations to the existing system were proposed (i.e. a tangential position of the inlet and a centrally situated outlet). On the basis of a simplified model of circulative water flow, it was shown that the altered hydraulic system can considerably improve the situation.

  13. The Problem of Evolving a Genetic Code

    ERIC Educational Resources Information Center

    Woese, Carl R.

    1970-01-01

    Proposes models for the evolution of the genetic code and translation mechanisms. Suggests that the translation process is so complex and precise that it must have evolved in many stages, and that the evolution of the code was influenced by the constraints imposed by the evolving translation mechanism. (EB)

  14. Evolving Technologies: A View to Tomorrow

    ERIC Educational Resources Information Center

    Tamarkin, Molly; Rodrigo, Shelley

    2011-01-01

    Technology leaders must participate in strategy creation as well as operational delivery within higher education institutions. The future of higher education--the view to tomorrow--is irrevocably integrated and intertwined with evolving technologies. This article focuses on two specific evolving technologies: (1) alternative IT sourcing; and (2)…

  15. Evolving Technologies: A View to Tomorrow

    ERIC Educational Resources Information Center

    Tamarkin, Molly; Rodrigo, Shelley

    2011-01-01

    Technology leaders must participate in strategy creation as well as operational delivery within higher education institutions. The future of higher education--the view to tomorrow--is irrevocably integrated and intertwined with evolving technologies. This article focuses on two specific evolving technologies: (1) alternative IT sourcing; and (2)…

  16. What Technology? Reflections on Evolving Services

    ERIC Educational Resources Information Center

    Collins, Sharon

    2009-01-01

    Each year, the members of the EDUCAUSE Evolving Technologies Committee identify and research the evolving technologies that are having--or are predicted to have--the most direct impact on higher education institutions. The committee members choose the relevant topics, write white papers, and present their findings at the EDUCAUSE annual…

  17. Comparison of molecular breeding values based on within- and across-breed training in beef cattle

    USDA-ARS?s Scientific Manuscript database

    Background Although the efficacy of genomic predictors based on within-breed training looks promising, it is necessary to develop and evaluate across-breed predictors for the technology to be fully applied in the beef industry. The efficacies of genomic predictors trained in one breed and utilized ...

  18. Inheritance of evolved resistance to a novel herbicide (pyroxasulfone).

    PubMed

    Busi, Roberto; Gaines, Todd A; Vila-Aiub, Martin M; Powles, Stephen B

    2014-03-01

    Agricultural weeds have rapidly adapted to intensive herbicide selection and resistance to herbicides has evolved within ecological timescales. Yet, the genetic basis of broad-spectrum generalist herbicide resistance is largely unknown. This study aims to determine the genetic control of non-target-site herbicide resistance trait(s) that rapidly evolved under recurrent selection of the novel lipid biosynthesis inhibitor pyroxasulfone in Lolium rigidum. The phenotypic segregation of pyroxasulfone resistance in parental, F1 and back-cross (BC) families was assessed in plants exposed to a gradient of pyroxasulfone doses. The inheritance of resistance to chemically dissimilar herbicides (cross-resistance) was also evaluated. Evolved resistance to the novel selective agent (pyroxasulfone) is explained by Mendelian segregation of one semi-dominant allele incrementally herbicide-selected at higher frequency in the progeny. In BC families, cross-resistance is conferred by an incompletely dominant single major locus. This study confirms that herbicide resistance can rapidly evolve to any novel selective herbicide agents by continuous and repeated herbicide use. The results imply that the combination of herbicide options (rotation, mixtures or combinations) to exploit incomplete dominance can provide acceptable control of broad-spectrum generalist resistance-endowing monogenic traits. Herbicide diversity within a set of integrated management tactics can be one important component to reduce the herbicide selection intensity. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Data Publication: The Evolving Lifecyle

    NASA Astrophysics Data System (ADS)

    Studwell, S.; Elliott, J.; Anderson, A.

    2015-12-01

    Datasets are recognized as valuable information entities in their own right that, now and in the future, need to be available for citation, discovery, retrieval and reuse. The U.S. Department of Energy's Office of Scientific and Technical Information (OSTI) provides Digital Object Identifiers (DOIs) to DOE-funded data through partnership with DataCite. The Geothermal Data Repository (GDR) has been using OSTI's Data ID Service since summer, 2014 and is a success story for data publishing in several different ways. This presentation attributes the initial success to the insistence of DOE's Geothermal Technologies Office on detailed planning, robust data curation, and submitter participation. OSTI widely disseminates these data products across both U.S. and international platforms and continually enhances the Data ID Service to facilitate better linkage between published literature, supplementary data components, and the underlying datasets within the structure of the GDR repository. Issues of granularity in DOI assignment, the role of new federal government guidelines on public access to digital data, and the challenges still ahead will be addressed.

  20. Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies

    PubMed Central

    Ekman, Jan; Ericson, Per G.P

    2006-01-01

    Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative ‘Corvida’ branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such as Pyrrhocorax and Dendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care. PMID:16600890

  1. Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies.

    PubMed

    Ekman, Jan; Ericson, Per G P

    2006-05-07

    Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative 'Corvida' branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such as Pyrrhocorax and Dendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care.

  2. 78 FR 45494 - Plant Breeding Listening Session meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ...; ] DEPARTMENT OF AGRICULTURE Plant Breeding Listening Session meeting ACTION: Notice of a Plant Breeding... Agriculture (USDA) announces a Plant Breeding Listening Session stakeholder meeting for all interested plant breeding and cultivar development stakeholders. DATES: The Plant Breeding Listening Session will be held...

  3. The value of resequence data for poultry breeding: a primary layer breeder perspective.

    PubMed

    Fulton, Janet E

    2014-02-01

    Poultry breeding companies are facing a new paradigm. Since 2004, extensive resources have been developed to increase understanding of the fundamental biology of the chicken. The chicken genome has been sequenced and revised twice, millions of novel DNA variants have been identified, and new tools have been created that allow rapid and inexpensive detection of these DNA variations. These developments have led to the establishment of molecular-based breeding programs within major poultry breeding companies that are revolutionizing the primary poultry breeding industries. Costs of sequencing continue to drop and are predicted to eventually reach the point where it is feasible to sequence the entire genome of elite birds before selection. There are multiple challenges to be resolved before this information can be fully incorporated into a breeding program. These include handling and analyzing the extremely large data sets generated, understanding which genes, variants, or both are relevant for commercial production traits, development of new bio-informatic tools, and integration of molecular information with traditional breeding programs. The novel variation identified within elite commercial lines will lead to enhancements in commercial breeding programs. Applications of this information include whole genomic selection, parentage identification, trait association studies, and quality control.

  4. Breed-specific dog-dandruff allergens.

    PubMed

    Lindgren, S; Belin, L; Dreborg, S; Einarsson, R; Påhlman, I

    1988-08-01

    Fifty-one patients with clinical history of dog allergy were skin prick tested with eight individual standardized dog breed-allergen preparations, one mixed breed-allergen preparation (Poodle/Alsatian), dog-serum albumin, and histamine hydrochloride, 1 mg/ml. All extracts were characterized by crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis with a pool of sera from patients clinically sensitive to dog. The dog-breed extracts contained common antigens/allergens, as well as components represented only in one or two dog-breed extracts. The concentration corresponding 1000 BU/ml varied from 16 to 100 micrograms of protein per milliliter. The sensitivity of skin prick test was 67% to 88% for the various dog breed-allergen preparations, but only 18% for dog-serum albumin. Significant difference between the skin test response to different dog breed-allergen preparations indicating dog breed-specific allergens was obtained in 15% of the patients. There was no significant correlation between skin prick test results and symptoms related to a specific dog breed.

  5. Mean EPDs reported by different breeds

    USDA-ARS?s Scientific Manuscript database

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breeding stock against their ...

  6. Sugarcane Improvement Through Breeding and Biotechnology

    USDA-ARS?s Scientific Manuscript database

    The advancements in sugarcane breeding and the improvement of sugarcane through biotechnology have been reviewed by a team of leading sugarcane specialists from around the world. Topics covered in the breeding section include the evolution and origin of sugarcane, early history of conventional sugar...

  7. Breeding Perspectives and Programs at East Lansing

    USDA-ARS?s Scientific Manuscript database

    USDA-ARS sugar beet breeding activities for both Aphanomyces resistance and CMS/O-type conversion at East Lansing reach back to the 1940’s, with variety testing activities at Michigan State University reaching back to circa 1911. Many of those contributions are well known in the sugar beet breeding ...

  8. Breeding sugarcane for temperate and cold environments

    USDA-ARS?s Scientific Manuscript database

    Louisiana represents one of the world’s more temperate environments where sugarcane is commercially grown. Since its inception in the 1920s, The USDA-ARS breeding program at the Sugarcane Research Laboratory in Houma, Louisiana, U.S.A. has focused on breeding varieties adapted to this unique envir...

  9. Breeding commercial sugarcane varieties for the industry

    USDA-ARS?s Scientific Manuscript database

    Recent literature suggests that sugarcane breeding in the United States has reached a sugar yield plateau. If so, this could have huge implications for the future of the industry and breeding per se because yield improvement might have to be achieved through secondary, non-sugar-related traits, or t...

  10. Genetic conservation in applied tree breeding programs.

    Treesearch

    R. Johnson; B. St. Clair; S. Lipow

    2001-01-01

    This paper reviews how population size and structure impacts the maintenance of genetic variation in breeding and gene resource populations. We discuss appropriate population sizes for low frequency alleles and point out some examples of low frequency alleles in the literature. Development of appropriate breeding populations and gene resource populations are discussed...

  11. Bull breeding soundness, semen evaluation and cattle productivity.

    PubMed

    Chenoweth, P J; McPherson, F J

    2016-06-01

    The bull breeding soundness evaluation (BBSE) has evolved as a cost-effective veterinary procedure which provides benefits such as risk-reduction and improvements in strategic bull usage, herd fertility and economics. Semen evaluation is an important component of the BBSE when performed appropriately; a consideration that is increasingly addressed by third party andrology laboratories. The combination of competent physical/reproductive exams (including scrotal circumference measurements) and semen evaluations can contribute greatly to the fertility and economics of individual herds as well as adding to understanding of those factors which affect cattle fertility. Despite such advantages, there remain challenges in achieving full acceptance of BBSEs, particularly by the dairy industry and in developing countries.

  12. Breeding experience, alternative reproductive strategies and reproductive success in a captive colony of zebra finches (Taeniopygia guttata).

    PubMed

    Baran, Nicole M; Adkins-Regan, Elizabeth

    2014-01-01

    Birds exhibit a remarkable diversity of different reproductive strategies both between and within species. Species such as the zebra finch (Taeniopygia guttata) may evolve the flexible use of alternative reproductive strategies, as well as benefit from prior breeding experience, which allows them to adaptively respond to unpredictable environments. In birds, the flexible use of alternative reproductive strategies, such as extra-pair mating, has been reported to be associated with fast reproduction, high mortality and environmental variability. However, little is known about the role of previous breeding experience in the adaptive use of alternative reproductive strategies. Here we performed an in-depth study of reproductive outcomes in a population of domesticated zebra finches, testing the impact of prior breeding experience on the use of alternative reproductive strategies and reproductive success. We provide evidence that older females with prior breeding experience are quicker to initiate a clutch with a new partner and have increased success in chick rearing, even in a captive colony of zebra finches with minimal foraging demands. We also find evidence that the breeding experience of other females in the same social group influences reproductive investment by female zebra finches. Furthermore, we demonstrate that the use of alternative reproductive strategies in female zebra finches is associated with previous failed breeding attempts with the same pair partner. The results provide evidence that age and breeding experience play important roles in the flexible use of both facultative and adaptive reproductive strategies in female zebra finches.

  13. Breeding Experience, Alternative Reproductive Strategies and Reproductive Success in a Captive Colony of Zebra Finches (Taeniopygia guttata)

    PubMed Central

    Baran, Nicole M.; Adkins-Regan, Elizabeth

    2014-01-01

    Birds exhibit a remarkable diversity of different reproductive strategies both between and within species. Species such as the zebra finch (Taeniopygia guttata) may evolve the flexible use of alternative reproductive strategies, as well as benefit from prior breeding experience, which allows them to adaptively respond to unpredictable environments. In birds, the flexible use of alternative reproductive strategies, such as extra-pair mating, has been reported to be associated with fast reproduction, high mortality and environmental variability. However, little is known about the role of previous breeding experience in the adaptive use of alternative reproductive strategies. Here we performed an in-depth study of reproductive outcomes in a population of domesticated zebra finches, testing the impact of prior breeding experience on the use of alternative reproductive strategies and reproductive success. We provide evidence that older females with prior breeding experience are quicker to initiate a clutch with a new partner and have increased success in chick rearing, even in a captive colony of zebra finches with minimal foraging demands. We also find evidence that the breeding experience of other females in the same social group influences reproductive investment by female zebra finches. Furthermore, we demonstrate that the use of alternative reproductive strategies in female zebra finches is associated with previous failed breeding attempts with the same pair partner. The results provide evidence that age and breeding experience play important roles in the flexible use of both facultative and adaptive reproductive strategies in female zebra finches. PMID:24587051

  14. Social networks: Evolving graphs with memory dependent edges

    NASA Astrophysics Data System (ADS)

    Grindrod, Peter; Parsons, Mark

    2011-10-01

    The plethora of digital communication technologies, and their mass take up, has resulted in a wealth of interest in social network data collection and analysis in recent years. Within many such networks the interactions are transient: thus those networks evolve over time. In this paper we introduce a class of models for such networks using evolving graphs with memory dependent edges, which may appear and disappear according to their recent history. We consider time discrete and time continuous variants of the model. We consider the long term asymptotic behaviour as a function of parameters controlling the memory dependence. In particular we show that such networks may continue evolving forever, or else may quench and become static (containing immortal and/or extinct edges). This depends on the existence or otherwise of certain infinite products and series involving age dependent model parameters. We show how to differentiate between the alternatives based on a finite set of observations. To test these ideas we show how model parameters may be calibrated based on limited samples of time dependent data, and we apply these concepts to three real networks: summary data on mobile phone use from a developing region; online social-business network data from China; and disaggregated mobile phone communications data from a reality mining experiment in the US. In each case we show that there is evidence for memory dependent dynamics, such as that embodied within the class of models proposed here.

  15. Warning signals evolve to disengage Batesian mimics.

    PubMed

    Franks, Daniel W; Ruxton, Graeme D; Sherratt, Thomas N

    2009-01-01

    Prey that are unprofitable to attack are typically conspicuous in appearance. Conventional theory assumes that these warning signals have evolved in response to predator receiver biases. However, such biases might be a symptom rather than a cause of warning signals. We therefore examine an alternative theory: that conspicuousness evolves in unprofitable prey to avoid confusion with profitable prey. One might wonder why unprofitable prey do not find a cryptic means to be distinct from profitable prey, reducing both their risk of confusion with profitable prey and their rate of detection by predators. Here we present the first coevolutionary model to allow for Batesian mimicry and signals with different levels of detectability. We find that unprofitable prey do indeed evolve ways of distinguishing themselves using cryptic signals, particularly when appearance traits can evolve in multiple dimensions. However, conspicuous warning signals readily evolve in unprofitable prey when there are more ways to look different from the background than to match it. Moreover, the more unprofitable the prey species, the higher its evolved conspicuousness. Our results provide strong support for the argument that unprofitable species evolve conspicuous signals to avoid confusion with profitable prey and indicate that peak shift in conspicuousness-linked traits is a major factor in its establishment.

  16. Sex, long life and the evolutionary transition to cooperative breeding in birds.

    PubMed

    Downing, Philip A; Cornwallis, Charlie K; Griffin, Ashleigh S

    2015-10-07

    Long life is a typical feature of individuals living in cooperative societies. One explanation is that group living lowers mortality, which selects for longer life. Alternatively, long life may make the evolution of cooperation more likely by ensuring a long breeding tenure, making helping behaviour and queuing for breeding positions worthwhile. The benefit of queuing will, however, depend on whether individuals gain indirect fitness benefits while helping, which is determined by female promiscuity. Where promiscuity is high and therefore the indirect fitness benefits of helping are low, cooperation can still be favoured by an even longer life span. We present the results of comparative analyses designed to test the likelihood of a causal relationship between longevity and cooperative breeding by reconstructing ancestral states of cooperative breeding across birds, and by examining the effect of female promiscuity on the relationship between these two traits. We found that long life makes the evolution of cooperation more likely and that promiscuous cooperative species are exceptionally long lived. These results make sense of promiscuity in cooperative breeders and clarify the importance of life-history traits in the evolution of cooperative breeding, illustrating that cooperation can evolve via the combination of indirect and direct fitness benefits.

  17. When mothers need others: The impact of hominin life history evolution on cooperative breeding.

    PubMed

    Kramer, Karen L; Otárola-Castillo, Erik

    2015-07-01

    The evolution of cooperative breeding is particularly complex in humans because many other traits that directly affect parental care (shorter birth intervals, increased offspring survivorship, juvenile dependence, and older ages at dispersal) also emerge during the Pleistocene. If human cooperative breeding is ancient, it likely evolved in a hominin lacking a fully modern life history. However, the impact that changing life history traits has on parental care and cooperative breeding has not been analytically investigated. We develop an exploratory model to simulate an economic problem that would have arisen over the course of hominin life history evolution to identify those transitions that produced the strongest pressures for cooperative childrearing. The model generates two central predictions. First, help within maternal-offspring groups can support early changes in juvenile dependence, dispersal age, birth intervals, and fertility. If so, maternal-juvenile cooperation may be an important but understudied step in the evolution of human cooperative breeding. Second, pressure to recruit adult cooperation is most pronounced under more derived conditions of late dispersal and later ages of juvenile dependence, with a strong interaction at short birth intervals. Our findings indicate that changes in life history traits that affect parental care are critical in considering background selective forces that shaped the evolution of cooperative breeding.

  18. Sex, long life and the evolutionary transition to cooperative breeding in birds

    PubMed Central

    Downing, Philip A.; Cornwallis, Charlie K.; Griffin, Ashleigh S.

    2015-01-01

    Long life is a typical feature of individuals living in cooperative societies. One explanation is that group living lowers mortality, which selects for longer life. Alternatively, long life may make the evolution of cooperation more likely by ensuring a long breeding tenure, making helping behaviour and queuing for breeding positions worthwhile. The benefit of queuing will, however, depend on whether individuals gain indirect fitness benefits while helping, which is determined by female promiscuity. Where promiscuity is high and therefore the indirect fitness benefits of helping are low, cooperation can still be favoured by an even longer life span. We present the results of comparative analyses designed to test the likelihood of a causal relationship between longevity and cooperative breeding by reconstructing ancestral states of cooperative breeding across birds, and by examining the effect of female promiscuity on the relationship between these two traits. We found that long life makes the evolution of cooperation more likely and that promiscuous cooperative species are exceptionally long lived. These results make sense of promiscuity in cooperative breeders and clarify the importance of life-history traits in the evolution of cooperative breeding, illustrating that cooperation can evolve via the combination of indirect and direct fitness benefits. PMID:26400743

  19. Breeding system evolution influenced the geographic expansion and diversification of the core Corvoidea (Aves: Passeriformes).

    PubMed

    Marki, Petter Z; Fabre, Pierre-Henri; Jønsson, Knud A; Rahbek, Carsten; Fjeldså, Jon; Kennedy, Jonathan D

    2015-07-01

    Birds vary greatly in their life-history strategies, including their breeding systems, which range from brood parasitism to a system with multiple nonbreeding helpers at the nest. By far the most common arrangement, however, is where both parents participate in raising the young. The traits associated with parental care have been suggested to affect dispersal propensity and lineage diversification, but to date tests of this potential relationship at broad temporal and spatial scales have been limited. Here, using data from a globally distributed group of corvoid birds in concordance with state-dependent speciation and extinction models, we suggest that pair breeding is associated with elevated speciation rates. Estimates of transition between breeding systems imply that cooperative lineages frequently evolve biparental care, whereas pair breeders rarely become cooperative. We further highlight that these groups have differences in their spatial distributions, with pair breeders overrepresented on islands, and cooperative breeders mainly found on continents. Finally, we find that speciation rates appear to be significantly higher on islands compared to continents. These results imply that the transition from cooperative breeding to pair breeding was likely a significant contributing factor facilitating dispersal across tropical archipelagos, and subsequent world-wide phylogenetic expansion among the core Corvoidea.

  20. Endometritis: Managing Persistent Post-Breeding Endometritis.

    PubMed

    Canisso, Igor F; Stewart, Jamie; Coutinho da Silva, Marco A

    2016-12-01

    Endometritis was rated as the third most common medical problem encountered in adult horses in North America. It is the leading cause of subfertility in broodmares and is a major contributor to economic loss in the horse breeding industry, with pregnancy rates reported to be as low as 21% in mares with severe endometritis. Endometritis may be categorized as: endometrosis (chronic degenerative endometritis), acute, chronic, active, dormant, subclinical, clinical, and persistent post-breeding. These classifications are not mutually exclusive, and mares may change categories within breeding seasons or estrous cycles or may fit in multiple classifications. This chapter will focus on discussing etiology and management strategies for mares affected by persistent post-breeding endometritis. Overall, these mares are considered subfertile but acceptable pregnancy and foaling rates can be achieved with appropriate breeding management.

  1. Genomic selection in animal breeding programs.

    PubMed

    van der Werf, Julius

    2013-01-01

    Genomic selection can have a major impact on animal breeding programs, especially where traits that are important in the breeding objective are hard to select for otherwise. Genomic selection provides more accurate estimates for breeding value earlier in the life of breeding animals, giving more selection accuracy and allowing lower generation intervals. From sheep to dairy cattle, the rates of genetic improvement could increase from 20 to 100 % and hard-to-measure traits can be improved more effectively.Reference populations for genomic selection need to be large, with thousands of animals measured for phenotype and genotype. The smaller the effective size of the breeding population, the larger the DNA segments they potentially share and the more accurate genomic prediction will be. The relative contribution of information from relatives in the reference population will be larger if the baseline accuracy is low, but such information is limited to closely related individuals and does not last over generations.

  2. Evolving modalities for femoropopliteal interventions.

    PubMed

    Ansel, Gary M; Lumsden, Alan B

    2009-04-01

    Despite technical advances in balloon design and technique, there has been little improvement of primary patency rates after balloon-based endovascular interventions for all but focal femoropopliteal lesions. Improving on stainless steel models, nitinol stents have been associated with favorable short- and midterm primary patency rates; studies with longer-term follow-up will be required to learn whether restenosis is ongoing, with continued loss of primary patency. Studies in recent years have shown varying incidences of mechanical fatigue leading to nitinol stent fracture. Covered stents are designed to prevent the tissue infiltration and intimal hyperplasia that can lead to bare metal in-stent restenosis. Several clinical studies, mainly single-center registries, have demonstrated a general effectiveness of the Hemobahn/Viabahn polytetrafluoroethylene-covered stent-grafts, approved for femoral arterial occlusive disease, and have helped to distinguish indications for use and to delineate possible failure modes. A multicenter randomized trial, which has completed enrollment, will compare the Viabahn with self-expanding bare nitinol stents. The primary use of drug-eluting stents (DES) has become routine clinical practice for coronary artery disease. The 2-phase multicenter randomized double-blind SIROCCO trials have been completed, with results published through 24 months. Follow-up demonstrated the feasibility and safety of deploying sirolimus-eluting stents in the femoropopliteal segment but failed to show superior efficacy for DES versus bare nitinol stents. However, the restenosis rates with bare metal stents were unexpectedly low. A paclitaxel-eluting stent without a polymer coating is currently being evaluated in the recently enrolled Zilver PTX randomized trial and international registry. A polymer-based everolimus-eluting stent is being evaluated for femoropopliteal use in the nonrandomized European STRIDES trial. Balloons coated with paclitaxel have

  3. Continuous Problem of Function Continuity

    ERIC Educational Resources Information Center

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  4. Continuous Problem of Function Continuity

    ERIC Educational Resources Information Center

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  5. Ecological constraints, life history traits and the evolution of cooperative breeding.

    PubMed

    Hatchwell; Komdeur

    2000-06-01

    The ecological constraints hypothesis is widely accepted as an explanation for the evolution of delayed dispersal in cooperatively breeding birds. Intraspecific studies offer the strongest support. Observational studies have demonstrated a positive association between the severity of ecological constraints and the prevalence of cooperation, and experimental studies in which constraints on independent breeding were relaxed resulted in helpers moving to adopt the vacant breeding opportunities. However, this hypothesis has proved less successful in explaining why cooperative breeding has evolved in some species or lineages but not in others. Comparative studies have failed to identify ecological factors that differ consistently between cooperative and noncooperative species. The life history hypothesis, which emphasizes the role of life history traits in the evolution of cooperative breeding, offers a solution to this difficulty. A recent analysis showed that low adult mortality and low dispersal predisposed certain lineages to show cooperative behaviour, given the right ecological conditions. This represents an important advance, not least by offering an explanation for the patchy phylogenetic distribution of cooperative breeding. We discuss the complementary nature of these two hypotheses and suggest that rather than regarding life history traits as predisposing and ecological factors as facilitating cooperation, they are more likely to act in concert. While acknowledging that different cooperative systems may be a consequence of different selective pressures, we suggest that to identify the key differences between cooperative and noncooperative species, a broad constraints hypothesis that incorporates ecological and life history traits in a single measure of 'turnover of breeding opportunities' may provide the most promising avenue for future comparative studies. Copyright 2000 The Association for the Study of Animal Behaviour.

  6. Within-breed heterozygosity of canine single nucleotide polymorphisms identified by across-breed comparison.

    PubMed

    Brouillette, J A; Venta, P J

    2002-12-01

    Identification of single nucleotide polymorphisms (SNPs) by DNA sequence comparison across breeds is a strategy for developing genetic markers that are useful for many breeds. However, the heterozygosity of SNPs identified in this way might be severely reduced within breeds by inbreeding or genetic drift in the small effective population size of a breed (population subdivision). The effect of inbreeding and population subdivision on heterozygosity of SNPs in dog breeds has never been investigated in a systematic way. We determined the genotypes of dogs from three divergent breeds for SNPs in four canine genes (ACTC, LMNA, SCGB, and TYMS) identified by across-breed DNA sequence comparison, and compared the genotype frequencies to those expected under Hardy-Weinberg equilibrium (HWE). Although population subdivision significantly skewed allele frequencies across breeds for two of the SNPs, the deviations of observed heterozygosities compared with those expected within breeds were minimal. These results indicate that across-breed DNA sequence comparison is a reasonable strategy for identifying SNPs that are useful within many canine breeds.

  7. Genomic evaluation of regional dairy cattle breeds in single-breed and multibreed contexts.

    PubMed

    Jónás, D; Ducrocq, V; Fritz, S; Baur, A; Sanchez, M-P; Croiseau, P

    2017-02-01

    An important prerequisite for high prediction accuracy in genomic prediction is the availability of a large training population, which allows accurate marker effect estimation. This requirement is not fulfilled in case of regional breeds with a limited number of breeding animals. We assessed the efficiency of the current French routine genomic evaluation procedure in four regional breeds (Abondance, Tarentaise, French Simmental and Vosgienne) as well as the potential benefits when the training populations consisting of males and females of these breeds are merged to form a multibreed training population. Genomic evaluation was 5-11% more accurate than a pedigree-based BLUP in three of the four breeds, while the numerically smallest breed showed a < 1% increase in accuracy. Multibreed genomic evaluation was beneficial for two breeds (Abondance and French Simmental) with maximum gains of 5 and 8% in correlation coefficients between yield deviations and genomic estimated breeding values, when compared to the single-breed genomic evaluation results. Inflation of genomic evaluation of young candidates was also reduced. Our results indicate that genomic selection can be effective in regional breeds as well. Here, we provide empirical evidence proving that genetic distance between breeds is only one of the factors affecting the efficiency of multibreed genomic evaluation.

  8. Carry-over body mass effect from winter to breeding in a resident seabird, the little penguin.

    PubMed

    Salton, Marcus; Saraux, Claire; Dann, Peter; Chiaradia, André

    2015-01-01

    Using body mass and breeding data of individual penguins collected continuously over 7 years (2002-2008), we examined carry-over effects of winter body mass on timing of laying and breeding success in a resident seabird, the little penguin (Eudyptula minor). The austral winter month of July consistently had the lowest rate of colony attendance, which confirmed our expectation that penguins work hard to find resources at this time between breeding seasons. Contrary to our expectation, body mass in winter (July) was equal or higher than in the period before ('moult-recovery') and after ('pre-breeding') in 5 of 7 years for males and in all 7 years for females. We provided evidence of a carry-over effect of body mass from winter to breeding; females and males with higher body mass in winter were more likely to breed early and males with higher body mass in winter were likely to breed successfully. Sex differences might relate to sex-specific breeding tasks, where females may use their winter reserves to invest in egg-laying, whereas males use their winter reserves to sustain the longer fasts ashore during courtship. Our findings suggest that resident seabirds like little penguins can also benefit from a carry-over effect of winter body mass on subsequent breeding.

  9. Patterns of molecular genetic variation among cat breeds.

    PubMed

    Menotti-Raymond, Marilyn; David, Victor A; Pflueger, Solveig M; Lindblad-Toh, Kerstin; Wade, Claire M; O'Brien, Stephen J; Johnson, Warren E

    2008-01-01

    Genetic variation in cat breeds was assessed utilizing a panel of short tandem repeat (STR) loci genotyped in 38 cat breeds and 284 single-nucleotide polymorphisms (SNPs) genotyped in 24 breeds. Population structure in cat breeds generally reflects their recent ancestry and absence of strong breed barriers between some breeds. There is a wide range in the robustness of population definition, from breeds demonstrating high definition to breeds with as little as a third of their genetic variation partitioning into a single population. Utilizing the STRUCTURE algorithm, there was no clear demarcation of the number of population subdivisions; 16 breeds could not be resolved into independent populations, the consequence of outcrossing in established breeds to recently developed breeds with common ancestry. These 16 breeds were divided into 6 populations. Ninety-six percent of cats in a sample set of 1040 were correctly assigned to their classified breed or breed group/population. Average breed STR heterozygosities ranged from moderate (0.53; Havana, Korat) to high (0.85; Norwegian Forest Cat, Manx). Most of the variation in cat breeds was observed within a breed population (83.7%), versus 16.3% of the variation observed between populations. The hierarchical relationships of cat breeds is poorly defined as demonstrated by phylogenetic trees generated from both STR and SNP data, though phylogeographic grouping of breeds derived completely or in part from Southeast Asian ancestors was apparent.

  10. Molecular breeding in Brassica for salt tolerance: importance of microsatellite (SSR) markers for molecular breeding in Brassica

    PubMed Central

    Kumar, Manu; Choi, Ju-Young; Kumari, Nisha; Pareek, Ashwani; Kim, Seong-Ryong

    2015-01-01

    Salinity is one of the important abiotic factors for any crop management in irrigated as well as rainfed areas, which leads to poor harvests. This yield reduction in salt affected soils can be overcome by improving salt tolerance in crops or by soil reclamation. Salty soils can be reclaimed by leaching the salt or by cultivation of salt tolerance crops. Salt tolerance is a quantitative trait controlled by several genes. Poor knowledge about mechanism of its inheritance makes slow progress in its introgression into target crops. Brassica is known to be a good reclamation crop. Inter and intra specific variation within Brassica species shows potential of molecular breeding to raise salinity tolerant genotypes. Among the various molecular markers, SSR markers are getting high attention, since they are randomly sparsed, highly variable and show co-dominant inheritance. Furthermore, as sequencing techniques are improving and softwares to find SSR markers are being developed, SSR markers technology is also evolving rapidly. Comparative SSR marker studies targeting Arabidopsis thaliana and Brassica species which lie in the same family will further aid in studying the salt tolerance related QTLs and subsequent identification of the “candidate genes” and finding out the origin of important QTLs. Although, there are a few reports on molecular breeding for improving salt tolerance using molecular markers in Brassica species, usage of SSR markers has a big potential to improve salt tolerance in Brassica crops. In order to obtain best harvests, role of SSR marker driven breeding approaches play important role and it has been discussed in this review especially for the introgression of salt tolerance traits in crops. PMID:26388887

  11. Neural mechanisms underlying the evolvability of behaviour

    PubMed Central

    Katz, Paul S.

    2011-01-01

    The complexity of nervous systems alters the evolvability of behaviour. Complex nervous systems are phylogenetically constrained; nevertheless particular species-specific behaviours have repeatedly evolved, suggesting a predisposition towards those behaviours. Independently evolved behaviours in animals that share a common neural architecture are generally produced by homologous neural structures, homologous neural pathways and even in the case of some invertebrates, homologous identified neurons. Such parallel evolution has been documented in the chromatic sensitivity of visual systems, motor behaviours and complex social behaviours such as pair-bonding. The appearance of homoplasious behaviours produced by homologous neural substrates suggests that there might be features of these nervous systems that favoured the repeated evolution of particular behaviours. Neuromodulation may be one such feature because it allows anatomically defined neural circuitry to be re-purposed. The developmental, genetic and physiological mechanisms that contribute to nervous system complexity may also bias the evolution of behaviour, thereby affecting the evolvability of species-specific behaviour. PMID:21690127

  12. Evolvability Characterization in the Context of SOA

    NASA Astrophysics Data System (ADS)

    Arciniegas H., Jose L.; Dueñas L., Juan C.

    Service-Oriented Architecture (SOA) is an architectural style which promotes reuse of self-contained services. These self-contained services allow a better consideration of software quality characteristics as they can be independently analyzed. In our work, the evolvability quality characteristic has been considered, due to its impact in the stages of Maintenance and Evolution (M&E) for the software enterprises. Three goals are underlined in this paper: first, the relationship between SOA and quality characteristics focusing on a precise definition of evolvability of a software product from the SOA perspective, second a M&E model for SOA, and finally, some experiences are presented in order to assess evolvability in real software products. Two case studies have been executed: the first one analyzing the evolvability of the OSGi framework. And in the second case, the model is used in local Small and Medium Enterprises (SMEs), where an improvement process has been executed.

  13. Neural mechanisms underlying the evolvability of behaviour.

    PubMed

    Katz, Paul S

    2011-07-27

    The complexity of nervous systems alters the evolvability of behaviour. Complex nervous systems are phylogenetically constrained; nevertheless particular species-specific behaviours have repeatedly evolved, suggesting a predisposition towards those behaviours. Independently evolved behaviours in animals that share a common neural architecture are generally produced by homologous neural structures, homologous neural pathways and even in the case of some invertebrates, homologous identified neurons. Such parallel evolution has been documented in the chromatic sensitivity of visual systems, motor behaviours and complex social behaviours such as pair-bonding. The appearance of homoplasious behaviours produced by homologous neural substrates suggests that there might be features of these nervous systems that favoured the repeated evolution of particular behaviours. Neuromodulation may be one such feature because it allows anatomically defined neural circuitry to be re-purposed. The developmental, genetic and physiological mechanisms that contribute to nervous system complexity may also bias the evolution of behaviour, thereby affecting the evolvability of species-specific behaviour.

  14. Breeding objectives for Targhee sheep.

    PubMed

    Borg, R C; Notter, D R; Kuehn, L A; Kott, R W

    2007-11-01

    Breeding objectives were developed for Targhee sheep under rangeland production conditions. Traits considered were those for which EPD were available from the US National Sheep Improvement Program and included direct and maternal effects on 120-d weaning weight (WW and MM, respectively); yearling weight (YW); yearling fleece weight, fiber diameter, and staple length; and percent lamb crop (PLC), measured as the number of lambs born per 100 ewes lambing. A bioeconomic model was used to predict the effects of a change of 1 additive SD in EPD for each trait, holding all other traits constant at their mean, on animal performance, feed requirements, feed costs, and economic returns. Resulting economic weightings were then used to derive selection indexes. Indexes were derived separately for 3 prolificacy levels (1.41, 1.55, and 1.70 lambs/ewe lambing), 2 triplet survival levels (50 and 67%), 2 lamb pricing policies (with or without discounting of prices for heavy feeder lambs), and 3 forage cost scenarios (renting pasture, purchasing hay, or reducing flock size to accommodate increased nutrient requirements for production). Increasing PLC generally had the largest impact on profitability, although an increase in WW was equally important, with low feed costs and no discounting of prices for heavy feeder lambs. Increases in PLC were recommended at all 3 prolificacy levels, but with low triplet survival the value of increasing PLC eventually declined as the mean litter size increased to approximately 2.15 lambs/ewe lambing and above. Increasing YW (independent of WW) increased ewe maintenance costs and reduced profitability. Predicted changes in breeding values for WW and YW under index selection varied with lamb pricing policy and feed costs. With low feed costs or no discounts for heavy lambs, YW increased at a modest rate in association with increasing WW, but with high feed costs or discounting of heavy lambs, genetic trends in WW were reduced by approximately 50% to

  15. Continuation Education.

    ERIC Educational Resources Information Center

    Fremont Unified School District, CA.

    The Fremont, California Unified School District organized a continuing education program through a workshop held in the summer of 1968. This paper presents the results of that workshop. Following a statement of philosophy, an outline of the characteristics of the continuation student, and an outline of the functions of the program, an overview of…

  16. Breeding bald eagles in captivity

    USGS Publications Warehouse

    Maestrelli, J.R.; Wiemeyer, Stanley N.

    1975-01-01

    A 7-year-old female Bald Eagle from Alabama was paired with a 4-year-old Alaskan male in a large flight pen during December 1969. Both birds were free of physical defects when originally placed in the pen but the female was blind in one eye prior to the 1973 breeding season.....Nesting first occurred during 1971 when at least two eggs were laid; all but one, which showed no sign of embryonic development after being incubated for 56 days, were broken by the adult birds. Two of three eggs laid in 1972 hatched. Both young died a few days after hatching following a period of inclement weather. Three eggs were laid and hatched during 1973. Antagonism between the nestlings was observed soon after hatching and may have been responsible for the unobserved death of one nestling, two days after the third young hatched. The two remaining young were raised by the adult birds and eventually left the nest 85 days after the first egg hatched. Incubation periods for the 1972-73 clutches averaged 35 days. No renesting attempts were made by the eagles during the 3.year period.

  17. Flow cytometry in plant breeding.

    PubMed

    Ochatt, Sergio J

    2008-07-01

    Since the first report on the flow cytometric study of plant material 35 years ago, analyzing the nuclear DNA content of field bean, an ever increasing number of applications of FCM has been developed and applied in plant science and industry, but a similar length of time elapsed before the appearance of the first complete volume devoted to FCM of plant cells. Most published information on the uses of FCM addresses various aspects of animal (including human) cell biology, thus failing to provide a pertinent substitute. FCM represents an ideal means for the analysis of both cells and subcellular particles, with a potentially large number of parameters analyzed both rapidly, simultaneously, and quantitatively, thereby furnishing statistically exploitable data and allowing for an accurate and facilitated detection of subpopulations. It is, indeed, the summation of these facts that has established FCM as an important, and sometimes essential, tool for the understanding of fundamental mechanisms and processes underlying plant growth, development, and function. In this review, special attention is paid to FCM as applied to plant cells in the context of plant breeding, and some new and less well-known uses of it for plants will be discussed.

  18. Breeding season survival and breeding incidence of female Mottled Ducks on the upper Texas gulf coast

    USGS Publications Warehouse

    Rigby, Elizabeth A.; Haukos, David A.

    2012-01-01

    Previous Mottled Duck (Anas fulvigula) studies suggested that high female breeding season survival may be caused by low nesting effort, but few breeding season estimates of survival associated with nesting effort exist on the western Gulf Coast. Here, breeding season survival (N = 40) and breeding incidence (N = 39) were estimated for female Mottled Ducks on the upper Texas coast, 2006–2008. Females were fitted with backpack radio transmitters and visually relocated every 3–4 days. Weekly survival was estimated using the Known Fate procedure of program MARK with breeding incidence estimated as the annual proportion of females observed nesting or with broods. The top-ranked survival model included a body mass covariate and held weekly female survival constant across weeks and years (SW = 0.986, SE = 0.006). When compared to survival across the entire year estimated from previous band recovery and age ratio analysis, survival rate during the breeding season did not differ. Breeding incidence was well below 100% in all years and highly variable among years (15%–63%). Breeding season survival and breeding incidence were similar to estimates obtained with implant transmitters from the mid-coast of Texas. The greatest breeding incidence for both studies occurred when drought indices indicated average environmental moisture during the breeding season. The observed combination of low breeding incidence and high breeding season survival support the hypothesis of a trade-off between the ecological cost of nesting effort and survival for Mottled Duck females. Habitat cues that trigger nesting are unknown and should be investigated.

  19. First charge breeding results at CARIBU EBIS

    SciTech Connect

    Kondrashev, S. Barcikowski, A. Dickerson, C. Ostroumov, P. N. Sharamentov, S. Vondrasek, R.; Pikin, A.

    2015-01-09

    The Electron Beam Ion Source (EBIS) developed to breed CARIBU radioactive beams at ATLAS is currently in the off-line commissioning stage. The beam commissioning is being performed using a low emittance surface ionization source producing singly-charged cesium ions. The primary goal of the off-line commissioning is the demonstration of high-efficiency charge breeding in the pulsed injection mode. An overview of the final design of the CARIBU EBIS charge breeder, the off-line commissioning installation and the first results on charge breeding of stable cesium ions are presented and discussed.

  20. Breeding behavior of immature mourning doves

    USGS Publications Warehouse

    Irby, H.D.; Blankenship, L.H.

    1966-01-01

    Some immature mourning doves (Zenaidura mncroura) are capable of breeding in their first (calendar) year of life. The breeding activities of immatures observed in this study included calling, copulating, and nesting. Development of sexual structures such as cloacal papillae, oviduct openings, and gonads was also regarded as evidence of breeding potential. Immatures were identified principally by white-tipped wing coverts. Sexes were distinguished by behavioral characteristics. Males coo, perform flights, carry nest material, and attend nests during the day and females attend nests at night. Immatures were involved in at least ten nestings on two areas near Tucson, Arizona, in 1963. Five young fledged from these nests.

  1. Management and Breeding Soundness of Mature Bulls.

    PubMed

    Palmer, Colin W

    2016-07-01

    Mature bulls must be fed a balanced ration, vaccinated appropriately, and undergo a breeding soundness evaluation to ensure they meet what is required of a short, but intense breeding season. To be classified as a satisfactory potential breeder, minimum standards for physical soundness, scrotal circumference, sperm motility, and sperm morphology must be achieved using an accepted bull-breeding soundness evaluation format. Sperm production requires approximately 70 days. Heat and stress are the most common insults to spermatogenesis, causing an increase in morphologic abnormalities with obesity-associated scrotal fat accumulation being the most frequent cause of elevated testicular temperature in mature bulls.

  2. Book review: Oklahoma Breeding Bird Atlas

    USGS Publications Warehouse

    Peterjohn, Bruce G.

    2004-01-01

    The first North American breeding bird atlases were initiated during the 1970s. With atlases completed or ongoing in more than 40 U.S. states and most Canadian provinces, these projects are now familiar to professional ornithologists and amateur birders. This book provides the results of the Oklahoma Breeding Bird Atlas, the data for which were collected during 1997–2001. Its appearance less than 3 years after completing fieldwork is remarkable and everyone associated with its timely publication should be congratulated for their efforts.Review info: Oklahoma Breeding Bird Atlas. By Dan L. Reinking, 2004. ISBN: 0806136146, 528 pp.

  3. Husbandry and enclosure influences on penguin behavior and conservation breeding.

    PubMed

    Marshall, Andrew R; Deere, Nicolas J; Little, Holly A; Snipp, Ross; Goulder, Jackie; Mayer-Clarke, Stacey

    2016-09-01

    Multi-zoo comparisons of animal welfare are rare, and yet vital for ensuring continued improvement of zoo enclosures and husbandry. Methods are not standardized for the development of zoo enclosures based on multiple indicators, and case study species are required. This study compares behavior and breeding success to various enclosure and husbandry parameters for the Humboldt penguin, Spheniscus humboldti, for the development of improved enclosure design. Behavioral sampling was completed at Flamingo Land over a period of 8 months. Further data on behavior, enclosure design, and breeding success were collected via questionnaires, visits to zoos, and literature review. Breeding success was primarily influenced by colony age and number of breeding pairs, suggesting an important social influence on reproduction. Across zoos, there was also significant variation in behavior. The proportion of time spent in water varied between zoos (2-23%) and was used as an indicator of physical activity and natural behavior. Regression models revealed that water-use was best predicted by total enclosure area per penguin, followed by land area, with some evidence for positive influence of pool surface area per penguin. Predominantly linear/curvilinear increases in our biological indicators with enclosure parameters suggest that optimal conditions for S. humboldti were not met among the selected zoos. We propose revised minimum conditions for S. humboldti enclosure design, which exceed those in the existing husbandry guidelines. We present a framework for the evaluation of zoo enclosures and suggest that a rigorous scientific protocol be established for the design of new enclosures, based on multivariate methods. Zoo Biol. 35:385-397, 2016. © Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Territorial aggression does not feed back on testosterone in a multiple-brooded songbird species with breeding and non-breeding season territoriality, the European stonechat.

    PubMed

    Apfelbeck, Beate; Flinks, Heiner; Goymann, Wolfgang

    2017-01-01

    Testosterone mediates reproductive behaviours in male vertebrates. For example, breeding season territoriality depends on testosterone in many species of birds and in some, territorial interactions feed back on testosterone concentrations. However, the degree to which territorial behaviour and testosterone are associated differs even between species with seemingly similar life histories, especially between species that also defend territories outside the breeding season. Here, we investigate the link between territorial behaviour and testosterone in European stonechats. Previous studies found that territorial aggression in stonechats depends on testosterone in a breeding, but not in a non-breeding context. We investigated whether stonechats show a rise in testosterone during simulated territorial intrusions (STI) during the breeding season. Post-capture testosterone concentrations of males caught after an STI were not higher than those of males caught in a control situation regardless of breeding stage. However, most of the males would have been able to mount a testosterone response because the same individuals that did not increase testosterone during the STI showed a substantial increase in testosterone after injections of gonadotropin-releasing hormone (GnRH). GnRH-induced and post-capture testosterone concentrations were positively correlated and both decreased with successive breeding stages. Further, territory owners with a short latency to attack the decoy expressed higher post-capture testosterone concentrations than males with a longer latency to attack the decoy. Thus, there is no evidence for behavioural feedback on testosterone concentrations during male-male interactions in stonechats. In combination with previous studies our data suggest that testosterone functions as an on/off switch of high intensity territorial aggression during the breeding season in stonechats. The among-species variation in the androgen control of territorial behaviour may be

  5. Empirical determination of breed-of-origin of alleles in three-breed cross pigs.

    PubMed

    Sevillano, Claudia A; Vandenplas, Jeremie; Bastiaansen, John W M; Calus, Mario P L

    2016-08-04

    Although breeding programs for pigs and poultry aim at improving crossbred performance, they mainly use training populations that consist of purebred animals. For some traits, e.g. residual feed intake, the genetic correlation between purebred and crossbred performance is low and thus including crossbred animals in the training population is required. With crossbred animals, the effects of single nucleotide polymorphisms (SNPs) may be breed-specific because linkage disequilibrium patterns between a SNP and a quantitative trait locus (QTL), and allele frequencies and allele substitution effects of a QTL may differ between breeds. To estimate the breed-specific effects of alleles in a crossbred population, the breed-of-origin of alleles in crossbred animals must be known. This study was aimed at investigating the performance of an approach that assigns breed-of-origin of alleles in real data of three-breed cross pigs. Genotypic data were available for 14,187 purebred, 1354 F1, and 1723 three-breed cross pigs. On average, 93.0 % of the alleles of three-breed cross pigs were assigned a breed-of-origin without using pedigree information and 94.6 % with using pedigree information. The assignment percentage could be improved by allowing a percentage (fr) of the copies of a haplotype to be observed in a purebred population different from the assigned breed-of-origin. Changing fr from 0 to 20 %, increased assignment of breed-of-origin by 0.6 and 0.7 % when pedigree information was and was not used, respectively, which indicates the benefit of setting fr to 20 %. Breed-of-origin of alleles of three-breed cross pigs can be derived empirically without the need for pedigree information, with 93.7 % of the alleles assigned a breed-of-origin. Pedigree information is useful to reduce computation time and can slightly increase the percentage of assignments. Knowledge on the breed-of-origin of alleles allows the use of models that implement breed-specific effects of SNP

  6. The Ascent of Cat Breeds: Genetic Evaluations of Breeds and Worldwide Random Bred Populations

    PubMed Central

    Lipinski, Monika J.; Froenicke, Lutz; Baysac, Kathleen C.; Billings, Nicholas C.; Leutenegger, Christian M.; Levy, Alon M.; Longeri, Maria; Niini, Tirri; Ozpinar, Haydar; Slater, Margaret R.; Pedersen, Niels C.; Lyons, Leslie A.

    2008-01-01

    The diaspora of the modern cat was traced with microsatellite markers from the presumed site of domestication to distant regions of the world. Genetic data were derived from over 1100 individuals, representing seventeen random bred populations from five continents and twenty-two breeds. The Mediterranean was reconfirmed to be the probable site of domestication. Genetic diversity has remained broad throughout the world, with distinct genetic clustering in the Mediterranean basin, Europe/America, Asia and Africa. However, Asian cats appeared to have separated early and expanded in relative isolation. Most breeds were derived from indigenous cats of their purported regions of origin. However, the Persian and Japanese Bobtail were more aligned with European/American than Mediterranean basin or Asian clusters. Three recently derived breeds were not distinct from their parental breeds of origin. Pure breeding was associated with a loss of genetic diversity, however, this loss did not correlate with breed popularity or age. PMID:18060738

  7. The ascent of cat breeds: genetic evaluations of breeds and worldwide random-bred populations.

    PubMed

    Lipinski, Monika J; Froenicke, Lutz; Baysac, Kathleen C; Billings, Nicholas C; Leutenegger, Christian M; Levy, Alon M; Longeri, Maria; Niini, Tirri; Ozpinar, Haydar; Slater, Margaret R; Pedersen, Niels C; Lyons, Leslie A

    2008-01-01

    The diaspora of the modern cat was traced with microsatellite markers from the presumed site of domestication to distant regions of the world. Genetic data were derived from over 1100 individuals, representing 17 random-bred populations from five continents and 22 breeds. The Mediterranean was reconfirmed to be the probable site of domestication. Genetic diversity has remained broad throughout the world, with distinct genetic clustering in the Mediterranean basin, Europe/America, Asia and Africa. However, Asian cats appeared to have separated early and expanded in relative isolation. Most breeds were derived from indigenous cats of their purported regions of origin. However, the Persian and Japanese bobtail were more aligned with European/American than with Mediterranean basin or Asian clusters. Three recently derived breeds were not distinct from their parental breeds of origin. Pure breeding was associated with a loss of genetic diversity; however, this loss did not correlate with breed popularity or age.

  8. Familiar neighbors enhance breeding success in birds.

    PubMed Central

    Beletsky, L D; Orians, G H

    1989-01-01

    We tested the hypothesis that long-term familiarity with neighbors is advantageous by determining whether male red-winged blackbirds (Agelaius phoeniceus) breeding adjacent to familiar neighbors have better reproductive success than other males. Using data gathered during a 10-yr study of breeding success, we found that males with familiar neighbors fledged, on average, significantly more offspring annually than males without familiar neighbors. We also found that the same males, breeding in different years on the same territories, had significantly larger harems in the years they had familiar neighbors. Improved reproductive success was due to the males' abilities to attract more females to nest in their territories. Alternative hypotheses to explain the positive relationship between familiar neighbors and breeding success were not supported by our data. Relatively high reproductive success for breeders with long-term neighbors may provide a basis for the evolution of cooperative behavior in this and other species. PMID:2813369

  9. Cooperative breeding and monogamy in mammalian societies

    PubMed Central

    Lukas, Dieter; Clutton-Brock, Tim

    2012-01-01

    Comparative studies of social insects and birds show that the evolution of cooperative and eusocial breeding systems has been confined to species where females mate completely or almost exclusively with a single male, indicating that high levels of average kinship between group members are necessary for the evolution of reproductive altruism. In this paper, we show that in mammals, the evolution of cooperative breeding has been restricted to socially monogamous species which currently represent 5 per cent of all mammalian species. Since extra-pair paternity is relatively uncommon in socially monogamous and cooperatively breeding mammals, our analyses support the suggestion that high levels of average kinship between group members have played an important role in the evolution of cooperative breeding in non-human mammals, as well as in birds and insects. PMID:22279167

  10. Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle

    PubMed Central

    Hennicke, Janos C.; James, David J.; Weimerskirch, Henri

    2015-01-01

    In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi) were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas) allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle. PMID:26098941

  11. Perspectives on evolving dental care payment and delivery models.

    PubMed

    Rubin, Marcie S; Edelstein, Burton L

    2016-01-01

    Health care reform is well under way in the United States as reflected in evolving delivery, financing, and payment approaches that are affecting medicine ahead of dentistry. The authors explored health systems changes under way, distinguished historical and organizational differences between medicine and dentistry, and developed alternative models to characterize the relationships between these professions. The authors explored a range of medical payment approaches, including those tied to objective performance metrics, and their potential application to dentistry. Advances in understanding the essential role of oral health in general health have pulled dentistry into the broader discussion of care integration and payment reform. Dentistry's fit with primary and specialty medical care may take a variety of forms. Common provider payment approaches in dentistry-fee-for-service, capitation, and salary-are tied insufficiently to performance when measured as either health processes or health outcomes. Dentistry can anticipate potential payment reforms by observing changes already under way in medicine and by understanding alternative payment approaches that are tied to performance metrics, such as those now in development by the Dental Quality Alliance and others. Novel forms of dental practice may be expected to evolve continuously as medical-dental integration and payment reforms that promote accountability evolve. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  12. Economic evaluation of genomic breeding programs.

    PubMed

    König, S; Simianer, H; Willam, A

    2009-01-01

    The objective of this study was to compare a conventional dairy cattle breeding program characterized by a progeny testing scheme with different scenarios of genomic breeding programs. The ultimate economic evaluation criterion was discounted profit reflecting discounted returns minus discounted costs per cow in a balanced breeding goal of production and functionality. A deterministic approach mainly based on the gene flow method and selection index calculations was used to model a conventional progeny testing program and different scenarios of genomic breeding programs. As a novel idea, the modeling of the genomic breeding program accounted for the proportion of farmers waiting for daughter records of genotyped young bulls before using them for artificial insemination. Technical and biological coefficients for modeling were chosen to correspond to a German breeding organization. The conventional breeding program for 50 test bulls per year within a population of 100,000 cows served as a base scenario. Scenarios of genomic breeding programs considered the variation of costs for genotyping, selection intensity of cow sires, proportion of farmers waiting for daughter records of genotyped young bulls, and different accuracies of genomic indices for bulls and cows. Given that the accuracies of genomic indices are greater than 0.70, a distinct economic advantage was found for all scenarios of genomic breeding programs up to factor 2.59, mainly due to the reduction in generation intervals. Costs for genotyping were negligible when focusing on a population-wide perspective and considering additional costs for herdbook registration, milk recording, or keeping of bulls, especially if there is no need for yearly recalculation of effects of single nucleotide polymorphisms. Genomic breeding programs generated a higher discounted profit than a conventional progeny testing program for all scenarios where at least 20% of the inseminations were done by genotyped young bulls without

  13. Synthesizing time-evolving partially-coherent Schell-model sources

    NASA Astrophysics Data System (ADS)

    Van Zandt, Noah R.; Hyde, Milo W.; Bose-Pillai, Santasri R.; Voelz, David G.; Xiao, Xifeng; Fiorino, Steven T.

    2017-03-01

    Time-evolving simulation of sources with partial spatial and temporal coherence is sometimes instructive or necessary to explain optical coherence effects. Yet, existing time-evolving synthesis techniques often require prohibitive amounts of computer memory. This paper discusses three methods for the synthesis of continuous or pulsed time-evolving sources with nearly arbitrary spatial and temporal coherence. One method greatly reduces computer memory requirements, making this type of synthesis more practical. The utility of all three methods is demonstrated via a modified form of Young's experiment. Numerical simulation and laboratory results for time-averaged irradiance are presented and compared with theory to validate the synthesis techniques.

  14. Recent advances in evolvable systems--ICES 96 (International Conference on Evolvable Systems).

    PubMed

    Frank, I; Manderick, B; Higuchi, T

    1997-01-01

    This paper reviews the developments in evolvable hardware systems presented at the First International Conference on Evolvable Systems (ICES 96). The main body of the review gives an overview of the 34 papers presented orally, splitting them into three broad groups according to whether they involve (1) evolving a fit solution to a problem as a member of a population of competing candidates, (2) evolving solutions that can individually learn from and adapt to their environments, or (3) the embryonic growth of solutions. We also review the discussion sessions of the conference and give pointers to related upcoming events.

  15. Prunus transcription factors: breeding perspectives

    PubMed Central

    Bianchi, Valmor J.; Rubio, Manuel; Trainotti, Livio; Verde, Ignazio; Bonghi, Claudio; Martínez-Gómez, Pedro

    2015-01-01

    Many plant processes depend on differential gene expression, which is generally controlled by complex proteins called transcription factors (TFs). In peach, 1533 TFs have been identified, accounting for about 5.5% of the 27,852 protein-coding genes. These TFs are the reference for the rest of the Prunus species. TF studies in Prunus have been performed on the gene expression analysis of different agronomic traits, including control of the flowering process, fruit quality, and biotic and abiotic stress resistance. These studies, using quantitative RT-PCR, have mainly been performed in peach, and to a lesser extent in other species, including almond, apricot, black cherry, Fuji cherry, Japanese apricot, plum, and sour and sweet cherry. Other tools have also been used in TF studies, including cDNA-AFLP, LC-ESI-MS, RNA, and DNA blotting or mapping. More recently, new tools assayed include microarray and high-throughput DNA sequencing (DNA-Seq) and RNA sequencing (RNA-Seq). New functional genomics opportunities include genome resequencing and the well-known synteny among Prunus genomes and transcriptomes. These new functional studies should be applied in breeding programs in the development of molecular markers. With the genome sequences available, some strategies that have been used in model systems (such as SNP genotyping assays and genotyping-by-sequencing) may be applicable in the functional analysis of Prunus TFs as well. In addition, the knowledge of the gene functions and position in the peach reference genome of the TFs represents an additional advantage. These facts could greatly facilitate the isolation of genes via QTL (quantitative trait loci) map-based cloning in the different Prunus species, following the association of these TFs with the identified QTLs using the peach reference genome. PMID:26124770

  16. Analysis of breed effects on semen traits in light horse, warmblood, and draught horse breeds.

    PubMed

    Gottschalk, Maren; Sieme, Harald; Martinsson, Gunilla; Distl, Ottmar

    2016-05-01

    In the present study, systematic effects on semen quality traits were investigated in 381 stallions representing 22 breeds. All stallions were used for AI either at the Lower Saxon National Stud Celle or the North Rhine-Westphalian National Stud Warendorf. A total of 71,078 fresh semen reports of the years 2001 to 2014 were edited for analysis of gel-free volume, sperm concentration, total number of sperm, progressive motility, and total number of progressively motile sperm. Breed differences were studied for warmblood and light horse breeds of both national studs (model I) and for warmblood breeds and the draught horse breed Rhenish German Coldblood from the North Rhine-Westphalian National stud (model II) using mixed model procedures. The fixed effects of age class, year, and month of semen collection had significant influences on all semen traits in both analyses. A significant influence of the horse breed was found for all semen traits but gel-free volume in both statistical models. Comparing warmblood and light horse stallions of both national studs, we observed highest sperm concentrations, total numbers of sperm, and total numbers of progressively motile sperm in Anglo-Arabian stallions. The draught horse breed Rhenish German Coldblood had the highest least squares means for gel-free volume, whereas all other investigated semen traits were significantly lower in this breed compared to the warmblood stallions under study. The variance components among stallions within breeds were significant for all semen traits and accounted for 40% to 59% of the total variance. The between-breed-variance among stallions was not significant underlining the similar size of the random stallion effect in each of the horse breeds analyzed here. In conclusion, breed and stallion are accounting for a significant proportion of the variation in semen quality.

  17. [Pain caused by breeding: definition, judgment, pathogenesis].

    PubMed

    Herzog, A

    1997-02-01

    Special terms of the "German Animal Protection Law (section 11b)"and the "European Agreement for Protection of Domestic Animals" particularly "torture-breeding, genetic characteristics, well-being, soundness, pains, injuries and specific use" are commented. Examples of torture-breedings are discussed: Dog (Merle-faktor, brachycephalie, atrichosis), cat (Mans-factor, W-gene, folded-ears), birds (tuffs, ear-drops, tailesness, hypertrophy of bill-warts, abnormal position of tarsal-joints, hypertrophy of imposing behavior).

  18. Viability of the Alaskan breeding population of Steller’s eiders

    USGS Publications Warehouse

    Dunham, Kylee; Grand, James B.

    2016-10-11

    The U.S. Fish and Wildlife Service is tasked with setting objective and measurable criteria for delisting species or populations listed under the Endangered Species Act. Determining the acceptable threshold for extinction risk for any species or population is a challenging task, particularly when facing marked uncertainty. The Alaskan breeding population of Steller’s eiders (Polysticta stelleri) was listed as threatened under the Endangered Species Act in 1997 because of a perceived decline in abundance throughout their nesting range and geographic isolation from the Russian breeding population. Previous genetic studies and modeling efforts, however, suggest that there may be dispersal from the Russian breeding population. Additionally, evidence exists of population level nonbreeding events. Research was conducted to estimate population viability of the Alaskan breeding population of Steller’s eiders, using both an open and closed model of population process for this threatened population. Projections under a closed population model suggest this population has a 100 percent probability of extinction within 42 years. Projections under an open population model suggest that with immigration there is no probability of permanent extinction. Because of random immigration process and nonbreeding behavior, however, it is likely that this population will continue to be present in low and highly variable numbers on the breeding grounds in Alaska. Monitoring the winter population, which includes both Russian and Alaskan breeding birds, may offer a more comprehensive indication of population viability.

  19. Citrus breeding, genetics and genomics in Japan

    PubMed Central

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering. PMID:27069387

  20. Lysine Fermentation: History and Genome Breeding.

    PubMed

    Ikeda, Masato

    2016-11-11

    Lysine fermentation by Corynebacterium glutamicum was developed in 1958 by Kyowa Hakko Kogyo Co. Ltd. (current Kyowa Hakko Bio Co. Ltd.) and is the second oldest amino acid fermentation process after glutamate fermentation. The fundamental mechanism of lysine production, discovered in the early stages of the process's history, gave birth to the concept known as "metabolic regulatory fermentation," which is now widely applied to metabolite production. After the development of rational metabolic engineering, research on lysine production first highlighted the need for engineering of the central metabolism from the viewpoints of precursor supply and NADPH regeneration. Furthermore, the existence of active export systems for amino acids was first demonstrated for lysine in C. glutamicum, and this discovery has resulted in the current recognition of such exporters as an important consideration in metabolite production. Lysine fermentation is also notable as the first process to which genomics was successfully applied to improve amino acid production. The first global "genome breeding" strategy was developed using a lysine producer as a model; this has since led to new lysine producers that are more efficient than classical industrial producers. These advances in strain development technology, combined with recent systems-level approaches, have almost achieved the optimization of entire cellular systems as cell factories for lysine production. In parallel, the continuous improvement of the process has resulted not only in fermentation processes with reduced load on downstream processing but also in commercialization of various product forms according to their intended uses. Nowadays lysine fermentation underpins a giant lysine demand of more than 2 million metric tons per year.

  1. Evolving networks in the human epileptic brain

    NASA Astrophysics Data System (ADS)

    Lehnertz, Klaus; Ansmann, Gerrit; Bialonski, Stephan; Dickten, Henning; Geier, Christian; Porz, Stephan

    2014-01-01

    Network theory provides novel concepts that promise an improved characterization of interacting dynamical systems. Within this framework, evolving networks can be considered as being composed of nodes, representing systems, and of time-varying edges, representing interactions between these systems. This approach is highly attractive to further our understanding of the physiological and pathophysiological dynamics in human brain networks. Indeed, there is growing evidence that the epileptic process can be regarded as a large-scale network phenomenon. We here review methodologies for inferring networks from empirical time series and for a characterization of these evolving networks. We summarize recent findings derived from studies that investigate human epileptic brain networks evolving on timescales ranging from few seconds to weeks. We point to possible pitfalls and open issues, and discuss future perspectives.

  2. Metanetworks of artificially evolved regulatory networks

    NASA Astrophysics Data System (ADS)

    Danacı, Burçin; Erzan, Ayşe

    2016-04-01

    We study metanetworks arising in genotype and phenotype spaces, in the context of a model population of Boolean graphs evolved under selection for short dynamical attractors. We define the adjacency matrix of a graph as its genotype, which gets mutated in the course of evolution, while its phenotype is its set of dynamical attractors. Metanetworks in the genotype and phenotype spaces are formed, respectively, by genetic proximity and by phenotypic similarity, the latter weighted by the sizes of the basins of attraction of the shared attractors. We find that evolved populations of Boolean graphs form tree-like giant clusters in genotype space, while random populations of Boolean graphs are typically so far removed from each other genetically that they cannot form a metanetwork. In phenotype space, the metanetworks of evolved populations are super robust both under the elimination of weak connections and random removal of nodes.

  3. Sexual dimorphism in gender plasticity and its consequences for breeding system evolution.

    PubMed

    Delph, Lynda F

    2003-01-01

    Flowering plants are able to develop gametes throughout their lives. As a consequence, environmental conditions can impact this development and alter a plant's functional gender or the degree to which it achieves fitness through male or female function. Two dimorphic breeding systems are widespread among angiosperm families: gynodioecy (hermaphrodites and females) and dioecy (males and females). Gynodioecy can evolve into dioecy, via loss of female function on the hermaphrodites, or it can remain stable. Here I discuss how developmental plasticity of gender can impact the sex ratio of populations and thereby influence the transition of one breeding system into another. I review studies showing that greater plasticity of fruit production by hermaphrodites as compared with females causes sex ratios among populations to vary in response to environmental conditions, with higher female frequency expected in harsh or low-quality sites. I also review how dioecy may evolve in dry sites to avoid inbreeding and any consequent inbreeding depression. Taken together, these studies show the importance of understanding how ecological development affects functional gender and consequently the evolutionary stability or malleability of dimorphic breeding systems.

  4. Variable postpartum responsiveness among humans and other primates with "cooperative breeding": A comparative and evolutionary perspective.

    PubMed

    Hrdy, Sarah B

    2016-01-01

    This article is part of a Special Issue "Parental Care".Until recently, evolutionists reconstructing mother-infant bonding among human ancestors relied on nonhuman primate models characterized by exclusively maternal care, overlooking the highly variable responsiveness exhibited by mothers in species with obligate reliance on allomaternal care and provisioning. It is now increasingly recognized that apes as large-brained, slow maturing, and nutritionally dependent for so long as early humans were, could not have evolved unless "alloparents" (group members other than genetic parents), in addition to parents, had helped mothers to care for and provision offspring, a rearing system known as "cooperative breeding." Here I review situation-dependent maternal responses ranging from highly possessive to permissive, temporarily distancing, rejecting, or infanticidal, documented for a small subset of cooperatively breeding primates. As in many mammals, primate maternal responsiveness is influenced by physical condition, endocrinological priming, prior experience and local environments (especially related to security). But mothers among primates who evolved as cooperative breeders also appear unusually sensitive to cues of social support. In addition to more "sapient" or rational decision-making, humankind's deep history of cooperative breeding must be considered when trying to understand the extremely variable responsiveness of human mothers.

  5. Carry-over body mass effect from winter to breeding in a resident seabird, the little penguin

    PubMed Central

    Salton, Marcus; Saraux, Claire; Dann, Peter; Chiaradia, André

    2015-01-01

    Using body mass and breeding data of individual penguins collected continuously over 7 years (2002–2008), we examined carry-over effects of winter body mass on timing of laying and breeding success in a resident seabird, the little penguin (Eudyptula minor). The austral winter month of July consistently had the lowest rate of colony attendance, which confirmed our expectation that penguins work hard to find resources at this time between breeding seasons. Contrary to our expectation, body mass in winter (July) was equal or higher than in the period before (‘moult-recovery’) and after (‘pre-breeding’) in 5 of 7 years for males and in all 7 years for females. We provided evidence of a carry-over effect of body mass from winter to breeding; females and males with higher body mass in winter were more likely to breed early and males with higher body mass in winter were likely to breed successfully. Sex differences might relate to sex-specific breeding tasks, where females may use their winter reserves to invest in egg-laying, whereas males use their winter reserves to sustain the longer fasts ashore during courtship. Our findings suggest that resident seabirds like little penguins can also benefit from a carry-over effect of winter body mass on subsequent breeding. PMID:26064587

  6. Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

    PubMed Central

    Krams, Indrikis; Krama, Tatjana

    2002-01-01

    When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities. PMID:12495502

  7. Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

    PubMed

    Krams, Indrikis; Krama, Tatjana

    2002-11-22

    When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities.

  8. JavaGenes: Evolving Graphs with Crossover

    NASA Technical Reports Server (NTRS)

    Globus, Al; Atsatt, Sean; Lawton, John; Wipke, Todd

    2000-01-01

    Genetic algorithms usually use string or tree representations. We have developed a novel crossover operator for a directed and undirected graph representation, and used this operator to evolve molecules and circuits. Unlike strings or trees, a single point in the representation cannot divide every possible graph into two parts, because graphs may contain cycles. Thus, the crossover operator is non-trivial. A steady-state, tournament selection genetic algorithm code (JavaGenes) was written to implement and test the graph crossover operator. All runs were executed by cycle-scavagging on networked workstations using the Condor batch processing system. The JavaGenes code has evolved pharmaceutical drug molecules and simple digital circuits. Results to date suggest that JavaGenes can evolve moderate sized drug molecules and very small circuits in reasonable time. The algorithm has greater difficulty with somewhat larger circuits, suggesting that directed graphs (circuits) are more difficult to evolve than undirected graphs (molecules), although necessary differences in the crossover operator may also explain the results. In principle, JavaGenes should be able to evolve other graph-representable systems, such as transportation networks, metabolic pathways, and computer networks. However, large graphs evolve significantly slower than smaller graphs, presumably because the space-of-all-graphs explodes combinatorially with graph size. Since the representation strongly affects genetic algorithm performance, adding graphs to the evolutionary programmer's bag-of-tricks should be beneficial. Also, since graph evolution operates directly on the phenotype, the genotype-phenotype translation step, common in genetic algorithm work, is eliminated.

  9. How the first biopolymers could have evolved.

    PubMed Central

    Abkevich, V I; Gutin, A M; Shakhnovich, E I

    1996-01-01

    In this work, we discuss a possible origin of the first biopolymers with stable unique structures. We suggest that at the prebiotic stage of evolution, long organic polymers had to be compact to avoid hydrolysis and had to be soluble and thus must not be exceedingly hydrophobic. We present an algorithm that generates such sequences for model proteins. The evolved sequences turn out to have a stable unique structure, into which they quickly fold. This result illustrates the idea that the unique three-dimensional native structures of first biopolymers could have evolved as a side effect of nonspecific physicochemical factors acting at the prebiotic stage of evolution. PMID:8570645

  10. 50 CFR 15.24 - Permits for cooperative breeding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Permits for cooperative breeding. 15.24... PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.24 Permits for cooperative breeding. (a) Application requirements for permits for cooperative breeding....

  11. 50 CFR 15.24 - Permits for cooperative breeding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Permits for cooperative breeding. 15.24... PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.24 Permits for cooperative breeding. (a) Application requirements for permits for cooperative breeding....

  12. 50 CFR 15.24 - Permits for cooperative breeding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 1 2014-10-01 2014-10-01 false Permits for cooperative breeding. 15.24... PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.24 Permits for cooperative breeding. (a) Application requirements for permits for cooperative breeding....

  13. Breeding strategies for north central tree improvement programs

    Treesearch

    Ronald P. Overton; Hyun Kang

    1985-01-01

    The rationales and concepts of long-term tree breeding are discussed and compared with those for short-term breeding. A model breeding program is reviewed which maximizes short-term genetic gain for currently important traits and provides genetic resources that can be used effectively in future short-term breeding. The resources of the north-central region are examined...

  14. 50 CFR 15.24 - Permits for cooperative breeding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.24 Permits for cooperative breeding. (a) Application requirements for permits for cooperative breeding. Each... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Permits for cooperative breeding. 15.24...

  15. Historical use of cultivars as parents in Florida and Louisiana sugarcane breeding program

    USDA-ARS?s Scientific Manuscript database

    Sugarcane (Saccharum L. spp. hybrids) growers depend on breeding programs for new, high-yielding cultivars that have resistance to abiotic and biotic stresses, so breeders continually seek out widely adapted, high yielding germplasm to be used as parents for their programs. Cultivars are sometimes u...

  16. Integrating molecular tools and conventional approaches in the Oregon State University hazelnut breeding program

    Treesearch

    Shawn A. Mehlenbacher

    2012-01-01

    The Oregon State University (OSU) hazelnut breeding program, initiated in 1969, continues to develop new cultivars for the hazelnut industry that combine suitability to the blanched kernel market with resistance to eastern filbert blight (EFB) caused by Anisogramma anomala. Oregon's hazelnut growers support the program through the Oregon...

  17. Effect of stand width and adjacent habitat on breeding bird communities in bottomland hardwoods

    Treesearch

    John C. Kilgo; Robert A. Sargent

    1998-01-01

    Bottomland hardwood forests support an abundant and diverse avifauna, but area of this forest type has been reduced, and current projections indicate continued declines. The authors compared breeding bird abundance indices and species richness among bottomland hardwood stands ranging in width from 1,000 m and enclosed by forested habitat. They also...

  18. Surveying The Digital Landscape: Evolving Technologies 2004. The EDUCAUSE Evolving Technologies Committee

    ERIC Educational Resources Information Center

    EDUCAUSE Review, 2004

    2004-01-01

    Each year, the members of the EDUCAUSE Evolving Technologies Committee identify and research the evolving technologies that are having the most direct impact on higher education institutions. The committee members choose the relevant topics, write white papers, and present their findings at the EDUCAUSE annual conference. This year, under the…

  19. Surveying The Digital Landscape: Evolving Technologies 2004. The EDUCAUSE Evolving Technologies Committee

    ERIC Educational Resources Information Center

    EDUCAUSE Review, 2004

    2004-01-01

    Each year, the members of the EDUCAUSE Evolving Technologies Committee identify and research the evolving technologies that are having the most direct impact on higher education institutions. The committee members choose the relevant topics, write white papers, and present their findings at the EDUCAUSE annual conference. This year, under the…

  20. Partitioning the Fitness Components of RNA Populations Evolving In Vitro

    PubMed Central

    Díaz Arenas, Carolina; Lehman, Niles

    2013-01-01

    All individuals in an evolving population compete for resources, and their performance is measured by a fitness metric. The performance of the individuals is relative to their abilities and to the biotic surroundings – the conditions under which they are competing – and involves many components. Molecules evolving in a test tube can also face complex environments and dynamics, and their fitness measurements should reflect the complexity of various contributing factors as well. Here, the fitnesses of a set of ligase ribozymes evolved by the continuous in vitro evolution system were measured. During these evolution cycles there are three different catalytic steps, ligation, reverse transcription, and forward transcription, each with a potential differential influence on the total fitness of each ligase. For six distinct ligase ribozyme genotypes that resulted from continuous evolution experiments, the rates of reaction were measured for each catalytic step by tracking the kinetics of enzymes reacting with their substrates. The reaction products were analyzed for the amount of product formed per time. Each catalytic step of the evolution cycle was found to have a differential incidence in the total fitness of the ligases, and therefore the total fitness of any ligase cannot be inferred from only one catalytic step of the evolution cycle. Generally, the ribozyme-directed ligation step tends to impart the largest effect on overall fitness. Yet it was found that the ligase genotypes have different absolute fitness values, and that they exploit different stages of the overall cycle to gain a net advantage. This is a new example of molecular niche partitioning that may allow for coexistence of more than one species in a population. The dissection of molecular events into multiple components of fitness provides new insights into molecular evolutionary studies in the laboratory, and has the potential to explain heretofore counterintuitive findings. PMID:24391957

  1. Captive breeding and reintroduction of the endangered masked bobwhite

    USGS Publications Warehouse

    Carpenter, J.W.; Gabel, R.R.; Goodwin, J.G.

    1991-01-01

    Efforts to restore the endangered masked bobwhite (Colinus virginianus ridgwayi) to its former range have required 1) habitat acquisition, restoration, and preservation; 2) captive propagation; and 3) reintroduction .bf captive-bred stock. In its role to recover the masked bobwhite, the Patuxent Wildlife Research Center (U.S. Fish and Wildli e Service) has refined captive breeding techniques; provided captive-produced stock for release; conducted field research on the distribution, limiting factors, and habitat characteristics of this species; and developed release methods. Techniques for the husbandry and captive management, breeding, artificial incubation and hatching of eggs, and rearing of young of the masked bobwhite have been developed. Successful reintroduction techniques for the masked bobwhite have included prerelease conditioning and/or cross-fostering of captive-reared masked bobwhite chicks to a wild-caught, related, vasectomized bobwhite species and their release to the wild as family units. In addition, the establishment by the U. S. Fish and Wildlife Service of the Buenos Aires National Wildlife Refuge in 1985 has further enhanced the potential for establishing a self-sustaining population of the masked bobwhite in the U. S. Through continued releases and active management of habitat, therefore, it is believed that the masked bobwhite can become permanently established at the refuge to ensure its continued survival in the wild.

  2. Life History Correlates and Extinction Risk of Capital-Breeding Fishes

    SciTech Connect

    Jager, Yetta; Vila-Gispert, Dr Anna; Rose, Kenneth A.

    2008-03-01

    We consider a distinction for fishes, often made for birds and reptiles, between capital-breeding and income-breeding species. Species that follow a capital-breeding strategy tend to evolve longer intervals between reproductive events and tend to have characteristics that we associate with higher extinction risk. To examine whether these ideas are relevant for fishes, we assembled life-history data for fish species, including an index of extinction risk, the interval between spawning events, the degree of parental care, and whether or not the species migrates to spawn. These data were used to evaluate two hypotheses: 1) fish species with a major accessory activity to spawning (migration or parental care) spawn less often and 2) fish species that spawn less often are at greater risk of extinction. We tested these hypotheses by applying two alternative statistical methods that account for phylogenetic correlation in cross-taxon comparisons. The two methods predicted average intervals between spawning events 0.13 to 0.20 years longer for fishes with a major accessory activity. Both accessories, above-average parental care and spawning migration, were individually associated with longer average spawning intervals. We conclude that the capital-breeding paradigm is relevant for fishes. We also confirmed the second hypothesis, that species in higher IUCN extinction risk categories had longer average spawning intervals. Further research is needed to understand the relationship between extinction risk and spawning interval, within the broader context of life history traits and aquatic habitats.

  3. Eleven years of breeding efforts to combat cassava brown streak disease

    PubMed Central

    Kawuki, Robert Sezi; Kaweesi, Tadeo; Esuma, Williams; Pariyo, Anthony; Kayondo, Ismail Siraj; Ozimati, Alfred; Kyaligonza, Vincent; Abaca, Alex; Orone, Joseph; Tumuhimbise, Robooni; Nuwamanya, Ephraim; Abidrabo, Philip; Amuge, Teddy; Ogwok, Emmanuel; Okao, Geoffrey; Wagaba, Henry; Adiga, Gerald; Alicai, Titus; Omongo, Christopher; Bua, Anton; Ferguson, Morag; Kanju, Edward; Baguma, Yona

    2016-01-01

    Cassava (Manihot esculenta Crantz) production is currently under threat from cassava brown streak disease (CBSD), a disease that is among the seven most serious obstacles to world’s food security. Three issues are of significance for CBSD. Firstly, the virus associated with CBSD, has co-evolved with cassava outside its center of origin for at least 90 years. Secondly, that for the last 74 years, CBSD was only limited to the low lands. Thirdly, that most research has largely focused on CBSD epidemiology and virus diversity. Accordingly, this paper focuses on CBSD genetics and/or breeding and hence, presents empirical data generated in the past 11 years of cassava breeding in Uganda. Specifically, this paper provides: 1) empirical data on CBSD resistance screening efforts to identify sources of resistance and/or tolerance; 2) an update on CBSD resistance population development comprising of full-sibs, half-sibs and S1 families and their respective field performances; and 3) insights into chromosomal regions and genes involved in CBSD resistance based on genome wide association analysis. It is expected that this information will provide a foundation for harmonizing on-going CBSD breeding efforts and consequently, inform the future breeding interventions aimed at combating CBSD. PMID:27795681

  4. Cognitive consequences of cooperative breeding in primates?

    PubMed

    Burkart, Judith Maria; van Schaik, Carel P

    2010-01-01

    Several hypotheses propose that cooperative breeding leads to increased cognitive performance, in both nonhuman and human primates, but systematic evidence for such a relationship is missing. A causal link might exist because motivational and cognitive processes necessary for the execution and coordination of helping behaviors could also favor cognitive performance in contexts not directly related to caregiving. In callitrichids, which among primates rely most strongly on cooperative breeding, these motivational and cognitive processes include attentional biases toward monitoring others, the ability to coordinate actions spatially and temporally, increased social tolerance, increased responsiveness to others' signals, and spontaneous prosociality. These processes are likely to enhance performance particularly in socio-cognitive contexts. Therefore, cooperatively breeding primates are expected to outperform their independently breeding sister taxa in socio-cognitive tasks. We evaluate this prediction by reviewing the literature and comparing cognitive performance in callitrichids with that of their sister taxa, i.e. squirrel monkeys, which are independent breeders, and capuchin monkeys, which show an intermediate breeding system. Consistent with our prediction, this review reveals that callitrichids systematically and significantly outperform their sister taxa in the socio-cognitive, but not in the non-social domain. This comparison is complemented with more qualitative evaluations of prosociality and cognitive performance in non-primate cooperative breeders, which suggest that among mammals, cooperative breeding generally produces conditions conducive to socio-cognitive performance. In the hominid lineage, however, the adoption of extensive allomaternal care presumably resulted in more pervasive cognitive consequences, because the motivational consequences of cooperative breeding was added to an ape-level cognitive system already capable of understanding simple

  5. Precocious breeding by yearling Giant Canada Geese

    USGS Publications Warehouse

    Drobney, R.D.; Checkett, J.M.; Coluccy, J.M.; Graber, D.A.

    1999-01-01

    Many species of waterfowl are capable of breeding as yearlings. In the subfamily Anserinae, however, reproduction normally does not commence until individuals reach two to four years of age (Rohwer 1992). Most published accounts indicate that Canada Geese (Branta canadensis) conform to the pattern typically found in other geese, deferring reproduction as yearlings and initiating breeding when birds are two years of age or older (Hanson 1962, Brakhage 1965, Bellrose 1980, Moser and Rusch 1989). The few documented exceptions (Brakhage 1965, Cooper 1978, MacInnes and Dunn 1988) suggest that the likelihood of a successful breeding attempt is higher for yearling males than females and that when early breeding occurs, one member of the pair is often at least two years old. Only two records of nesting attempts by yearling female Canada Geese have been published (Hall and McGilvrey 1971, Mickelson, 1975). In each case, the female produced some fertile eggs but deserted the nest before the eggs hatched.The observations noted above demonstrate that reproduction by yearling Canada Geese is physiolog ically possible for both sexes, but they also raise a number of interesting questions regarding why most individuals defer breeding during their first year. Energetic or nutritional constraints, and the inability of yearlings to secure and successfully defend a territory, are likely physiological (Elder 1946) and social (Brakhage 1965) impediments to early breeding From an evolutionary perspective, reduced reproductive success of yearlings relative to adults, and increased mortality associated with early breeding. also may contribute to deferred sexual maturity in waterfowl (Rohwer 1992).

  6. Across-breed EPD tables for the year 2016 adjusted to breed differences for birth year of 2014

    USDA-ARS?s Scientific Manuscript database

    Records of progeny of 18 breeds were used to estimate differences among the breeds for birth, weaning, and yearling weight and for maternal effects of weaning weight, among 15 of the 18 breeds for carcass marbling and ribeye area and among 14 of the 18 breeds for fat depth and carcass weight. The r...

  7. Across-breed EPD tables for the year 2011 adjusted to breed differences for birth year of 2009

    USDA-ARS?s Scientific Manuscript database

    Records of F1 and 3-way cross progeny of 18 breeds of sire and maternal grandsire, respectively, were used to estimate differences among the breeds for birth, weaning, and yearling weight and for maternal effects (16 breeds) of weaning weight and among 13 of the 18 breeds for carcass marbling, ribey...

  8. Across-breed EPD tables for the year 2012 adjusted to breed differences for birth year of 2010

    USDA-ARS?s Scientific Manuscript database

    Records of F1 and 3-way cross progeny of 18 breeds of sire and maternal grandsire, respectively, were used to estimate differences among the breeds for birth, weaning, and yearling weight and for maternal effects (16 breeds) of weaning weight and among 13 of the 18 breeds for carcass marbling, ribey...

  9. Apollo 16 Evolved Lithology Sodic Ferrogabbro

    NASA Technical Reports Server (NTRS)

    Zeigler, Ryan; Jolliff, B. L.; Korotev, R. L.

    2014-01-01

    Evolved lunar igneous lithologies, often referred to as the alkali suite, are a minor but important component of the lunar crust. These evolved samples are incompatible-element rich samples, and are, not surprisingly, most common in the Apollo sites in (or near) the incompatible-element rich region of the Moon known as the Procellarum KREEP Terrane (PKT). The most commonly occurring lithologies are granites (A12, A14, A15, A17), monzogabbro (A14, A15), alkali anorthosites (A12, A14), and KREEP basalts (A15, A17). The Feldspathic Highlands Terrane is not entirely devoid of evolved lithologies, and rare clasts of alkali gabbronorite and sodic ferrogabbro (SFG) have been identified in Apollo 16 station 11 breccias 67915 and 67016. Curiously, nearly all pristine evolved lithologies have been found as small clasts or soil particles, exceptions being KREEP basalts 15382/6 and granitic sample 12013 (which is itself a breccia). Here we reexamine the petrography and geochemistry of two SFG-like particles found in a survey of Apollo 16 2-4 mm particles from the Cayley Plains 62283,7-15 and 62243,10-3 (hereafter 7-15 and 10-3 respectively). We will compare these to previously reported SFG samples, including recent analyses on the type specimen of SFG from lunar breccia 67915.

  10. Did Language Evolve Like the Vertebrate Eye?

    ERIC Educational Resources Information Center

    Botha, Rudolf P.

    2002-01-01

    Offers a critical appraisal of the way in which the idea that human language or some of its features evolved like the vertebrate eye by natural selection is articulated in Pinker and Bloom's (1990) selectionist account of language evolution. Argues that this account is less than insightful because it fails to draw some of the conceptual…

  11. The Evolving Leadership Path of Visual Analytics

    SciTech Connect

    Kluse, Michael; Peurrung, Anthony J.; Gracio, Deborah K.

    2012-01-02

    This is a requested book chapter for an internationally authored book on visual analytics and related fields, coordianted by a UK university and to be published by Springer in 2012. This chapter is an overview of the leadship strategies that PNNL's Jim Thomas and other stakeholders used to establish visual analytics as a field, and how those strategies may evolve in the future.

  12. Evolving Neural Networks for Nonlinear Control.

    DTIC Science & Technology

    1996-09-30

    An approach to creating Amorphous Recurrent Neural Networks (ARNN) using Genetic Algorithms (GA) called 2pGA has been developed and shown to be...effective in evolving neural networks for the control and stabilization of both linear and nonlinear plants, the optimal control for a nonlinear regulator

  13. Did Language Evolve Like the Vertebrate Eye?

    ERIC Educational Resources Information Center

    Botha, Rudolf P.

    2002-01-01

    Offers a critical appraisal of the way in which the idea that human language or some of its features evolved like the vertebrate eye by natural selection is articulated in Pinker and Bloom's (1990) selectionist account of language evolution. Argues that this account is less than insightful because it fails to draw some of the conceptual…

  14. Thermal and Evolved-Gas Analyzer Illustration

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is a computer-aided drawing of the Thermal and Evolved-Gas Analyzer, or TEGA, on NASA's Phoenix Mars Lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. A Course Evolves-Physical Anthropology.

    ERIC Educational Resources Information Center

    O'Neil, Dennis

    2001-01-01

    Describes the development of an online physical anthropology course at Palomar College (California) that evolved from online tutorials. Discusses the ability to update materials on the Web more quickly than in traditional textbooks; creating Web pages that are readable by most Web browsers; test security issues; and clarifying ownership of online…

  16. Can Fusion and Fission Breeding Help Civilization Survive?

    NASA Astrophysics Data System (ADS)

    Manheiemr, Wallace

    2006-12-01

    As apparent from the title, this author feels that civilization faces a real threat, one which will become obvious and serious within the lifetimes of many readers of this article. This threat is not global warming, but lack of affordable energy. We take for granted turning on a light, or adjusting our thermostats in winter or summer, or filling our cars gas tank; and lose sight of the fact that there are huge and complicated industrial systems which make this possible. But as we run out of petroleum and natural gas, and worry about the environmental and climatic effects of burning coal on the required scale, how can this continue? This paper makes the case that breeding nuclear fuel, by both fusion and fission, is the only way our civilization as we know it, can continue beyond the next half century or so.

  17. Breeding programmes for smallholder sheep farming systems: II. Optimization of cooperative village breeding schemes.

    PubMed

    Gizaw, S; van Arendonk, J A M; Valle-Zárate, A; Haile, A; Rischkowsky, B; Dessie, T; Mwai, A O

    2014-10-01

    A simulation study was conducted to optimize a cooperative village-based sheep breeding scheme for Menz sheep of Ethiopia. Genetic gains and profits were estimated under nine levels of farmers' participation and three scenarios of controlled breeding achieved in the breeding programme, as well as under three cooperative flock sizes, ewe to ram mating ratios and durations of ram use for breeding. Under fully controlled breeding, that is, when there is no gene flow between participating (P) and non-participating (NP) flocks, profits ranged from Birr 36.9 at 90% of participation to Birr 21.3 at 10% of participation. However, genetic progress was not affected adversely. When there was gene flow from the NP to P flocks, profits declined from Birr 28.6 to Birr -3.7 as participation declined from 90 to 10%. Under the two-way gene flow model (i.e. when P and NP flocks are herded mixed in communal grazing areas), NP flocks benefited from the genetic gain achieved in the P flocks, but the benefits declined sharply when participation declined beyond 60%. Our results indicate that a cooperative breeding group can be established with as low as 600 breeding ewes mated at a ratio of 45 ewes to one ram, and the rams being used for breeding for a period of two years. This study showed that farmer cooperation is crucial to effect genetic improvement under smallholder low-input sheep farming systems.

  18. The sub-annual breeding cycle of a tropical seabird.

    PubMed

    Reynolds, S James; Martin, Graham R; Dawson, Alistair; Wearn, Colin P; Hughes, B John

    2014-01-01

    Breeding periodicity allows organisms to synchronise breeding attempts with the most favourable ecological conditions under which to raise offspring. For most animal species, ecological conditions vary seasonally and usually impose an annual breeding schedule on their populations; sub-annual breeding schedules will be rare. We use a 16-year dataset of breeding attempts by a tropical seabird, the sooty tern (Onychoprion fuscatus), on Ascension Island to provide new insights about this classical example of a population of sub-annually breeding birds that was first documented in studies 60 years previously on the same island. We confirm that the breeding interval of this population has remained consistently sub-annual. By ringing >17,000 birds and re-capturing a large sample of them at equivalent breeding stages in subsequent seasons, we reveal for the first time that many individual birds also consistently breed sub-annually (i.e. that sub-annual breeding is an individual as well as a population breeding strategy). Ascension Island sooty terns appear to reduce their courtship phase markedly compared with conspecifics breeding elsewhere. Our results provide rare insights into the ecological and physiological drivers of breeding periodicity, indicating that reduction of the annual cycle to just two life-history stages, breeding and moult, is a viable life-history strategy and that moult may determine the minimum time between breeding attempts.

  19. The Sub-Annual Breeding Cycle of a Tropical Seabird

    PubMed Central

    Reynolds, S. James; Martin, Graham R.; Dawson, Alistair; Wearn, Colin P.; Hughes, B. John

    2014-01-01

    Breeding periodicity allows organisms to synchronise breeding attempts with the most favourable ecological conditions under which to raise offspring. For most animal species, ecological conditions vary seasonally and usually impose an annual breeding schedule on their populations; sub-annual breeding schedules will be rare. We use a 16-year dataset of breeding attempts by a tropical seabird, the sooty tern (Onychoprion fuscatus), on Ascension Island to provide new insights about this classical example of a population of sub-annually breeding birds that was first documented in studies 60 years previously on the same island. We confirm that the breeding interval of this population has remained consistently sub-annual. By ringing >17000 birds and re-capturing a large sample of them at equivalent breeding stages in subsequent seasons, we reveal for the first time that many individual birds also consistently breed sub-annually (i.e. that sub-annual breeding is an individual as well as a population breeding strategy). Ascension Island sooty terns appear to reduce their courtship phase markedly compared with conspecifics breeding elsewhere. Our results provide rare insights into the ecological and physiological drivers of breeding periodicity, indicating that reduction of the annual cycle to just two life-history stages, breeding and moult, is a viable life-history strategy and that moult may determine the minimum time between breeding attempts. PMID:24714514

  20. Laboratory breeding of the short-lived annual killifish Nothobranchius furzeri.

    PubMed

    Polačik, Matej; Blažek, Radim; Reichard, Martin

    2016-08-01

    Turquoise killifish, Nothobranchius furzeri, have an intrinsically short life span, with a median life span of <6 months and a maximum (90%) life span of 9 months. This short life span, which is unique among vertebrates, evolved naturally and has resulted in N. furzeri becoming a widely used laboratory model species in aging research and other disciplines. Here, we describe a protocol for the maintenance and breeding of the species under laboratory conditions. We provide details for egg incubation, hatching, everyday care of juvenile and adult fish, breeding and treatment of most common diseases. Emphasis is given to the fact that the requirements of N. furzeri substantially differ from those of other fish model taxa; N. furzeri live brief lives and in nature undergo nonaquatic embryo development, with consequences for their laboratory culture.

  1. [Historic treasures of Swiss horse breeding].

    PubMed

    Meier, H

    2017-01-01

    Both a mandate of the Bernese Government (1705) and statements in the Georgica Helvetica of 1706 prove that Swiss horse breeding was lucrative and of good quality at that time. However, the political turmoil at the transition from the 18th to 19th century and excessive sales to France and Italy led to a severe drop in quantity as well in quality. The exhibition of horses in Aarau in 1865 showed a wretched state of the material. In the same year, Rudolf Zangger wrote a guide for the discussion of horse breeding in Switzerland. In the following year (1866), Johann Jakob Rychner published a report on horse breeding, and a further treatise on Swiss horse breeding by Johann Heinrich Hirzel followed in 1883. These publications created good and comprehensive fundamentals, which can still be considered valid. However history shows that the results and recommendations of these analyses barely led to improvements. Todays genomics with their possibilities open up a new era of animal breeding and raise bigger demands than ever.

  2. Resistance Genes in Global Crop Breeding Networks.

    PubMed

    Garrett, K A; Andersen, K F; Asche, F; Bowden, R L; Forbes, G A; Kulakow, P A; Zhou, B

    2017-08-31

    Resistance genes are a major tool for managing crop diseases. The networks of crop breeders who exchange resistance genes and deploy them in varieties help to determine the global landscape of resistance and epidemics, an important system for maintaining food security. These networks function as a complex adaptive system, with associated strengths and vulnerabilities, and implications for policies to support resistance gene deployment strategies. Extensions of epidemic network analysis can be used to evaluate the multilayer agricultural networks that support and influence crop breeding networks. Here, we evaluate the general structure of crop breeding networks for cassava, potato, rice, and wheat. All four are clustered due to phytosanitary and intellectual property regulations, and linked through CGIAR hubs. Cassava networks primarily include public breeding groups, whereas others are more mixed. These systems must adapt to global change in climate and land use, the emergence of new diseases, and disruptive breeding technologies. Research priorities to support policy include how best to maintain both diversity and redundancy in the roles played by individual crop breeding groups (public versus private and global versus local), and how best to manage connectivity to optimize resistance gene deployment while avoiding risks to the useful life of resistance genes. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

  3. Behavioral profiles of feline breeds in Japan.

    PubMed

    Takeuchi, Yukari; Mori, Yuji

    2009-08-01

    To clarify the behavioral profiles of 9 feline purebreds, 2 Persian subbreeds and the Japanese domestic cat, a questionnaire survey was distributed to 67 small-animal veterinarians. We found significant differences among breeds in all behavioral traits examined except for "inappropriate elimination". In addition, sexual differences were observed in certain behaviors, including "aggression toward cats", "general activity", "novelty-seeking", and "excitability". These behaviors were more common in males than females, whereas "nervousness" and "inappropriate elimination" were rated higher in females. When all breeds were categorized into four groups on the basis of a cluster analysis using the scores of two behavioral trait factors called "aggressiveness/sensitivity" and "vivaciousness", the group including Abyssinian, Russian Blue, Somali, Siamese, and Chinchilla breeds showed high aggressiveness/sensitivity and low vivaciousness. In contrast, the group including the American Shorthair and Japanese domestic cat displayed low aggressiveness/sensitivity and high vivaciousness, and the Himalayan and Persian group showed mild aggressiveness/sensitivity and very low vivaciousness. Finally, the group containing Maine Coon, Ragdoll, and Scottish Fold breeds displayed very low aggressiveness/sensitivity and low vivaciousness. The present results demonstrate that some feline behavioral traits vary by breed and/or sex.

  4. Improving the breed - Shuttle development

    NASA Technical Reports Server (NTRS)

    Brand, V.

    1985-01-01

    An evaluation is made of design improvements that have been made to the Space Shuttle System, and the performance gains obtained; the most important of these stem from efforts to refine procedures for rendezvous with stricken satellites, in order to repair them. Ascent performance has been improved through Space Shuttle Main Engine thrust improvements and external tank weight reductions. On-orbit living convenience has been enhanced by the addition of small sleeping compartments and a galley. Greater flexibility has been obtained for reentry and landing maneuvers. Attention is given to problems which continue to be posed by the thermal protection tiles.

  5. Protracted treatment with corticosterone reduces breeding success in a long-lived bird.

    PubMed

    Nelson, Bethany F; Daunt, Francis; Monaghan, Pat; Wanless, Sarah; Butler, Adam; Heidinger, Britt J; Newell, Mark; Dawson, Alistair

    2015-01-01

    Determining the physiological mechanisms underpinning life-history decisions is essential for understanding the constraints under which life-history strategies can evolve. In long-lived species, where the residual reproductive value of breeders is high, adult survival is a key contributor to lifetime reproductive success. We therefore expect that when adult survival is compromised during reproduction, mechanisms will evolve to redirect resources away from reproduction, with implications for reproductive hormones, adult body mass, nest attendance behaviour and breeding success. We investigated whether manipulating corticosterone, to simulate exposure to an environmental stressor, affected the secretion of prolactin and breeding success in the black-legged kittiwake Rissa tridactyla. We used implanted Alzet® osmotic pumps to administer corticosterone to incubating kittiwakes at a constant rate over a period of approximately 8days. Manipulated birds were compared with sham implanted birds and control birds, which had no implants. There was no significant difference in the body mass of captured individuals at the time of implantation and implant removal. Corticosterone-implanted males showed lower nest attendance during the chick rearing period compared to sham-implanted males; the opposite pattern was found in females. Corticosterone treated birds showed a marginally significant reduction in breeding success compared to sham-implanted individuals, with all failures occurring at least 1week after implant removal. However, prolactin concentrations at implant removal were not significantly different from initial values. We were unable to measure the profile of change in corticosterone during the experiment. However, our results suggest a delayed effect of elevated corticosterone on breeding success rather than an immediate suppression of prolactin concentrations causing premature failure.

  6. Genetic stability in the Icelandic horse breed.

    PubMed

    Campana, M G; Stock, F; Barrett, E; Benecke, N; Barker, G W W; Seetah, K; Bower, M A

    2012-08-01

    Despite the Icelandic horse enjoying great popularity worldwide, the breed's gene pool is small. This is because of a millennium of isolation on Iceland, population crashes caused by natural disasters and selective breeding. Populations with small effective population sizes are considered to be more at risk of selection pressures such as disease and environmental change. By analysing historic and modern mitochondrial DNA sequences and nuclear coat colour genes, we examined real-time population dynamics in the Icelandic horse over the last 150 years. Despite the small gene pool of this breed, we found that the effective population size and genetic profile of the Icelandic horse have remained stable over the studied time period.

  7. Breeding and genetics--historical perspective.

    PubMed

    Rishell, W A

    1997-08-01

    This paper is a review of selection methods that have been used in commercial breeding of table egg stocks, broilers, and turkeys, based on the author's experience. In addition, a number of historic developments that have shaped or influenced the selection process are listed and the significance of each is discussed. The merits of mass selection are noted and compared with the multiple forms of family selection, e.g., full or half sibs, progeny testing, and recurrent methods. Each of these methods is believed to have nearly universal application in applied breeding programs being practiced today. This review concludes that a combination of individual and family selection practices aimed at improving multiple traits simultaneously is required to remain a successful supplier of breeding stock to the current commercial industry.

  8. Toxoplasma gondii seroprevalence varies by cat breed.

    PubMed

    Must, Kärt; Hytönen, Marjo K; Orro, Toomas; Lohi, Hannes; Jokelainen, Pikka

    2017-01-01

    Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are taken into account. The studied breeds were the Birman, British Shorthair, Burmese, Korat, Norwegian Forest Cat, Ocicat, Persian, and Siamese. Plasma samples were analyzed for the presence of immunoglobulin G antibodies against T. gondii with a commercial direct agglutination test at dilution 1:40. The samples were accompanied by owner-completed questionnaires that provided background data on the cats. Overall, 41.12% of the 1121 cats tested seropositive, and the seroprevalence increased with age. The Burmese had the lowest seroprevalence (18.82%) and the Persian had the highest (60.00%). According to the final multivariable logistic regression model, the odds to test seropositive were four to seven times higher in Birmans, Ocicats, Norwegian Forest Cats, and Persians when compared with the Burmese, while older age and receiving raw meat were also risk factors for T. gondii seropositivity. This study showed that T. gondii seroprevalence varies by cat breed and identified being of certain breeds, older age, and receiving raw meat as risk factors for seropositivity.

  9. Competitive Advantage and its Sources in an Evolving Market

    NASA Astrophysics Data System (ADS)

    Zaridis, Apostolos D.

    2009-08-01

    In a continuously altered and evolving Market, as is the food manufacturing market, the main and long-lasting objective of firm that is the maximization of its wealth and consequently the continuous remaining in profit regions, appears that it is possible to be achieved via the obtainment and maintenance of diachronically long-term competitive advantage, which it will render the firm unique or leader force in a inexorable competition that is continuously extended in a globalized market. Various definitions and different regards are developed in regard to the competitive advantage and the way with which a firm it is possible, acquiring it, to star in the market in which it is activated. As result of sustainable competitive advantage in a firm comes the above the average performance. Abundance of resources and competences that are proposed as sources of competitive advantage in the resource-based view literature exists, while they are added continuously new based on empiric studies. In any case, it appears to suffer hierarchy of sources of competitive advantage, with regard to sustainability of these.

  10. Dust obscuration by an evolving galaxy population

    NASA Technical Reports Server (NTRS)

    Najita, Joan; Silk, Joseph; Wachter, Kenneth W.

    1990-01-01

    The effect of an evolving luminosity function (LF) on the ability of foreground galaxies to obscure background sources is discussed, using the Press-Schechter/CDM standard evolving LF model. Galaxies are modeled as simplified versions of local spirals and Poisson statistics are used to estimate the fraction of sky covered by intervening dusty galaxies and the mean optical depths due to these galaxies. The results are compared to those obtained in the case of nonevolving luminosity function in a low-density universe. It is found that evolution of the galaxy LF does not allow the quasar dust obscuration hypothesis to be sustained for dust disks with plausible sizes. Even in a low-density universe, where evolution at z = less than 10 is unimportant, large disk radii are needed to achieve the desired obscuring effect. The mean fraction of sky covered is presented as a function of the redshift z along with adequate diagram illustrations.

  11. The management of evolving bronchopulmonary dysplasia.

    PubMed

    Schulzke, Sven M; Pillow, J Jane

    2010-09-01

    Bronchopulmonary dysplasia (BPD) is associated with increased mortality and significant long-term cardiorespiratory and neurodevelopmental sequelae. Treatment of evolving BPD in the neonatal intensive care unit (NICU) is challenging due to the complex interplay of contributing risk factors which include preterm birth per se, supplemental oxygen, positive pressure ventilation, patent ductus arterious, and pre- and postnatal infection. Management of evolving BPD requires a multimodal approach including adequate nutrition, careful fluid management, effective and safe pharmacotherapy, and respiratory support aiming at minimal lung injury. Among pharmacological interventions, caffeine has the best risk-benefit profile. Systemic postnatal corticosteroids should be reserved to ventilated infants at highest risk of BPD who cannot be weaned from the ventilator. Several ongoing randomised trials are evaluating optimal oxygen saturation targets in preterm infants. The most beneficial respiratory support strategy to minimise lung injury remains unclear and requires further investigation. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. Evolved gas analysis of secondary organic aerosols

    SciTech Connect

    Grosjean, D.; Williams, E.L. II; Grosjean, E. ); Novakov, T. )

    1994-11-01

    Secondary organic aerosols have been characterized by evolved gas analysis (EGA). Hydrocarbons selected as aerosol precursors were representative of anthropogenic emissions (cyclohexene, cyclopentene, 1-decene and 1-dodecene, n-dodecane, o-xylene, and 1,3,5-trimethylbenzene) and of biogenic emissions (the terpenes [alpha]-pinene, [beta]-pinene and d-limonene and the sesquiterpene trans-caryophyllene). Also analyzed by EGA were samples of secondary, primary (highway tunnel), and ambient (urban) aerosols before and after exposure to ozone and other photochemical oxidants. The major features of the EGA thermograms (amount of CO[sub 2] evolved as a function of temperature) are described. The usefulness and limitations of EGA data for source apportionment of atmospheric particulate carbon are briefly discussed. 28 refs., 7 figs., 4 tabs.

  13. Breeding Astyanax mexicanus through Natural Spawning.

    PubMed

    Borowsky, Richard

    2008-11-01

    INTRODUCTIONMale and female Astyanax mexicanus can be bred successfully in tanks under appropriate conditions. Females should be maintained on a diet high in fats for 10-14 d before breeding. The transfer of a male and female into clean water in a fresh tank and a change (increase) in water temperature are cues for breeding. Newly fertilized eggs may also be obtained through in vitro fertilization. Note that blind fish should never be paired with eyed fish in illuminated aquaria, because the eyed fish are aggressive and will kill even much larger blind fish. Such matings must be carried out in the dark or by using in vitro fertilization.

  14. Age-specific breeding in Emperor Geese

    USGS Publications Warehouse

    Schmutz, J.A.

    2000-01-01

    I studied the frequency with which Emperor Geese (Chen canagica) of known age were observed breeding on the Yukon-Kuskokwim Delta, Alaska. No one- or two-year old geese were observed on nests. Three-year old geese bred at a lower rate than four-year old geese. These data suggest that patterns of age-specific breeding in Emperor Geese are similar to other sympatrically nesting, large bodied geese [Greater White-fronted Geese (Anser albifrons)] but delayed relative to smaller bodied geese [Cackling Canada Geese (Branta canadensis minima) and Pacific Black Brant (B. bernicla nigricans)].

  15. [Families and psychiatry: models and evolving links].

    PubMed

    Frankhauser, Adeline

    2016-01-01

    The role of the families of persons with severe psychiatric disorders (schizophrenia in particular) in the care of their relatives has recently evolved: once seen as pathogenic to be kept at a distance, the family is now recognised by professionals as a partner in the care process. The links between families and psychiatric institutions remain complex and marked by ambivalence and paradoxes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Design Space Issues for Intrinsic Evolvable Hardware

    NASA Technical Reports Server (NTRS)

    Hereford, James; Gwaltney, David

    2004-01-01

    This paper discusses the problem of increased programming time for intrinsic evolvable hardware (EM) as the complexity of the circuit grows. As the circuit becomes more complex, then more components will be required and a longer programming string, L, is required. We develop equations for the size of the population, n, and the number of generations required for the population to converge, based on L. Our analytical results show that even though the design search space grows as 2L (assuming a binary programming string), the number of circuit evaluations, n*ngen, only grows as O(Lg3), or slightly less than O(L). This makes evolvable techniques a good tool for exploring large design spaces. The major hurdle for intrinsic EHW is evaluation time for each possible circuit. The evaluation time involves downloading the bit string to the device, updating the device configuration, measuring the output and then transferring the output data to the control processor. Each of these steps must be done for each member of the population. The processing time of the computer becomes negligible since the selection/crossover/mutation steps are only done once per generation. Evaluation time presently limits intrinsic evolvable hardware techniques to designing only small or medium-sized circuits. To evolve large or complicated circuits, several researchers have proposed using hierarchical design or reuse techniques where submodules are combined together to form complex circuits. However, these practical approaches limit the search space of available designs and preclude utilizing parasitic coupling or other effects within the programmable device. The practical approaches also raise the issue of why intrinsic EHW techniques do not easily apply to large design spaces, since the analytical results show only an O(L) complexity growth.

  17. The evolving definition of systemic arterial hypertension.

    PubMed

    Ram, C Venkata S; Giles, Thomas D

    2010-05-01

    Systemic hypertension is an important risk factor for premature cardiovascular disease. Hypertension also contributes to excessive morbidity and mortality. Whereas excellent therapeutic options are available to treat hypertension, there is an unsettled issue about the very definition of hypertension. At what level of blood pressure should we treat hypertension? Does the definition of hypertension change in the presence of co-morbid conditions? This article covers in detail the evolving concepts in the diagnosis and management of hypertension.

  18. Quantum games on evolving random networks

    NASA Astrophysics Data System (ADS)

    Pawela, Łukasz

    2016-09-01

    We study the advantages of quantum strategies in evolutionary social dilemmas on evolving random networks. We focus our study on the two-player games: prisoner's dilemma, snowdrift and stag-hunt games. The obtained result show the benefits of quantum strategies for the prisoner's dilemma game. For the other two games, we obtain regions of parameters where the quantum strategies dominate, as well as regions where the classical strategies coexist.

  19. Nursing administration research: an evolving science.

    PubMed

    Murphy, Lyn Stankiewicz; Scott, Elaine S; Warshawsky, Nora E

    2014-12-01

    The nature and focus of nursing administrative research have evolved over time. Recently, the research agenda has primarily reflected the national health policy agenda. Although nursing research has traditionally been dominated by clinical interests, nursing administrative research has historically addressed the interface of reimbursement, quality, and care delivery systems. This article traces the evolution of nursing administrative research to answer questions relevant to scope, practice, and policy and suggests future directions.

  20. Transistor Level Circuit Experiments using Evolvable Hardware

    NASA Technical Reports Server (NTRS)

    Stoica, A.; Zebulum, R. S.; Keymeulen, D.; Ferguson, M. I.; Daud, Taher; Thakoor, A.

    2005-01-01

    The Jet Propulsion Laboratory (JPL) performs research in fault tolerant, long life, and space survivable electronics for the National Aeronautics and Space Administration (NASA). With that focus, JPL has been involved in Evolvable Hardware (EHW) technology research for the past several years. We have advanced the technology not only by simulation and evolution experiments, but also by designing, fabricating, and evolving a variety of transistor-based analog and digital circuits at the chip level. EHW refers to self-configuration of electronic hardware by evolutionary/genetic search mechanisms, thereby maintaining existing functionality in the presence of degradations due to aging, temperature, and radiation. In addition, EHW has the capability to reconfigure itself for new functionality when required for mission changes or encountered opportunities. Evolution experiments are performed using a genetic algorithm running on a DSP as the reconfiguration mechanism and controlling the evolvable hardware mounted on a self-contained circuit board. Rapid reconfiguration allows convergence to circuit solutions in the order of seconds. The paper illustrates hardware evolution results of electronic circuits and their ability to perform under 230 C temperature as well as radiations of up to 250 kRad.

  1. Evolving specialization of the arthropod nervous system.

    PubMed

    Jarvis, Erin; Bruce, Heather S; Patel, Nipam H

    2012-06-26

    The diverse array of body plans possessed by arthropods is created by generating variations upon a design of repeated segments formed during development, using a relatively small "toolbox" of conserved patterning genes. These attributes make the arthropod body plan a valuable model for elucidating how changes in development create diversity of form. As increasingly specialized segments and appendages evolved in arthropods, the nervous systems of these animals also evolved to control the function of these structures. Although there is a remarkable degree of conservation in neural development both between individual segments in any given species and between the nervous systems of different arthropod groups, the differences that do exist are informative for inferring general principles about the holistic evolution of body plans. This review describes developmental processes controlling neural segmentation and regionalization, highlighting segmentation mechanisms that create both ectodermal and neural segments, as well as recent studies of the role of Hox genes in generating regional specification within the central nervous system. We argue that this system generates a modular design that allows the nervous system to evolve in concert with the body segments and their associated appendages. This information will be useful in future studies of macroevolutionary changes in arthropod body plans, especially in understanding how these transformations can be made in a way that retains the function of appendages during evolutionary transitions in morphology.

  2. Estimating superpopulation size and annual probability of breeding for pond-breeding salamanders

    USGS Publications Warehouse

    Kinkead, K.E.; Otis, D.L.

    2007-01-01

    It has long been accepted that amphibians can skip breeding in any given year, and environmental conditions act as a cue for breeding. In this paper, we quantify temporary emigration or nonbreeding probability for mole and spotted salamanders (Ambystoma talpoideum and A. maculatum). We estimated that 70% of mole salamanders may skip breeding during an average rainfall year and 90% may skip during a drought year. Spotted salamanders may be more likely to breed, with only 17% avoiding the breeding pond during an average rainfall year. We illustrate how superpopulations can be estimated using temporary emigration probability estimates. The superpopulation is the total number of salamanders associated with a given breeding pond. Although most salamanders stay within a certain distance of a breeding pond for the majority of their life spans, it is difficult to determine true overall population sizes for a given site if animals are only captured during a brief time frame each year with some animals unavailable for capture at any time during a given year. ?? 2007 by The Herpetologists' League, Inc.

  3. To breed or not to breed: a seabird's response to extreme climatic events

    PubMed Central

    Cubaynes, Sarah; Doherty, Paul F.; Schreiber, E. A.; Gimenez, Olivier

    2011-01-01

    Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark–recapture dataset involving more than 11 000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities. PMID:20943677

  4. To breed or not to breed: a seabird's response to extreme climatic events.

    PubMed

    Cubaynes, Sarah; Doherty, Paul F; Schreiber, E A; Gimenez, Olivier

    2011-04-23

    Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark-recapture dataset involving more than 11,000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.

  5. Accuracy of genotype imputation in sheep breeds.

    PubMed

    Hayes, B J; Bowman, P J; Daetwyler, H D; Kijas, J W; van der Werf, J H J

    2012-02-01

    Although genomic selection offers the prospect of improving the rate of genetic gain in meat, wool and dairy sheep breeding programs, the key constraint is likely to be the cost of genotyping. Potentially, this constraint can be overcome by genotyping selection candidates for a low density (low cost) panel of SNPs with sparse genotype coverage, imputing a much higher density of SNP genotypes using a densely genotyped reference population. These imputed genotypes would then be used with a prediction equation to produce genomic estimated breeding values. In the future, it may also be desirable to impute very dense marker genotypes or even whole genome re-sequence data from moderate density SNP panels. Such a strategy could lead to an accurate prediction of genomic estimated breeding values across breeds, for example. We used genotypes from 48 640 (50K) SNPs genotyped in four sheep breeds to investigate both the accuracy of imputation of the 50K SNPs from low density SNP panels, as well as prospects for imputing very dense or whole genome re-sequence data from the 50K SNPs (by leaving out a small number of the 50K SNPs at random). Accuracy of imputation was low if the sparse panel had less than 5000 (5K) markers. Across breeds, it was clear that the accuracy of imputing from sparse marker panels to 50K was higher if the genetic diversity within a breed was lower, such that relationships among animals in that breed were higher. The accuracy of imputation from sparse genotypes to 50K genotypes was higher when the imputation was performed within breed rather than when pooling all the data, despite the fact that the pooled reference set was much larger. For Border Leicesters, Poll Dorsets and White Suffolks, 5K sparse genotypes were sufficient to impute 50K with 80% accuracy. For Merinos, the accuracy of imputing 50K from 5K was lower at 71%, despite a large number of animals with full genotypes (2215) being used as a reference. For all breeds, the relationship of

  6. Costs Associated with Equine Breeding in Kentucky

    NASA Astrophysics Data System (ADS)

    Walker, Cassandra L.

    There were approximately 9 million horses in the United States having a 102 billion impact on the U.S. economy (AHC, 2005). Over 1 million of those horses were involved in the breeding sector. In Kentucky, nearly 18% of the horse population have been involved in breeding. Managing an equine enterprise can be difficult, particularly given that many who undertake such endeavors do not have a background or education in business management. Kentucky Cooperative Extension has produced interactive spreadsheets to help horse owners better understand the costs associated with owning horses or managing certain equine businesses, including boarding and training operations. However, there has been little support for breeders. Therefore, the objectives of this study were to provide owners with a list of services offered for breeding and the costs associated with those services. Survey questions were created from a list of topics pertinent to equine breeding and from that list of questions, an electronic survey was created. The survey was sent via Qualtrics Survey Software to collect information on stallion and mare management costs as well as expenses related to owning and breeding. Question topics included veterinary and housing costs, management and advertising expenses, and membership fees. A total of 78 farms were selected from the 2013 breeder's listings for the Kentucky Quarter Horse Association (n = 39) and the Kentucky Thoroughbred Farm Managers' Club (n = 26), and other breed association contacts (n = 13). These farms were selected from the lists by outside individuals who were not related to the project. Participants were asked to answer all questions relevant to the farm. After the initial survey distribution, follow-up e-mails and phone calls were conducted in order to answer any questions participants might have had about the survey. Survey response rate was 32.1% (25 of 78 surveys returned). Farms in Kentucky had an average of two farm-owned and two outside

  7. eVolver: an optimization engine for evolving protein sequences to stabilize the respective structures.

    PubMed

    Brylinski, Michal

    2013-07-31

    Many structural bioinformatics approaches employ sequence profile-based threading techniques. To improve fold recognition rates, homology searching may include artificially evolved amino acid sequences, which were demonstrated to enhance the sensitivity of protein threading in targeting midnight zone templates. We describe implementation details of eVolver, an optimization algorithm that evolves protein sequences to stabilize the respective structures by a variety of potentials, which are compatible with those commonly used in protein threading. In a case study focusing on LARG PDZ domain, we show that artificially evolved sequences have quite high capabilities to recognize the correct protein structures using standard sequence profile-based fold recognition. Computationally design protein sequences can be incorporated in existing sequence profile-based threading approaches to increase their sensitivity. They also provide a desired linkage between protein structure and function in in silico experiments that relate to e.g. the completeness of protein structure space, the origin of folds and protein universe. eVolver is freely available as a user-friendly webserver and a well-documented stand-alone software distribution at http://www.brylinski.org/evolver.

  8. Evolving Multi Rover Systems in Dynamic and Noisy Environments

    NASA Technical Reports Server (NTRS)

    Tumer, Kagan; Agogino, Adrian

    2005-01-01

    In this chapter, we address how to evolve control strategies for a collective: a set of entities that collectively strives to maximize a global evaluation function that rates the performance of the full system. Addressing such problems by directly applying a global evolutionary algorithm to a population of collectives is unworkable because the search space is prohibitively large. Instead, we focus on evolving control policies for each member of the collective, where each member is trying to maximize the fitness of its own population. The main difficulty with this approach is creating fitness evaluation functions for the members of the collective that induce the collective to achieve high performance with respect to the system level goal. To overcome this difficulty, we derive member evaluation functions that are both aligned with the global evaluation function (ensuring that members trying to achieve high fitness results in a collective with high fitness) and sensitive to the fitness of each member (a member's fitness depends more on its own actions than on actions of other members). In a difficult rover coordination problem in dynamic and noisy environments, we show how to construct evaluation functions that lead to good collective behavior. The control policy evolved using aligned and member-sensitive evaluations outperforms global evaluation methods by up to a factor of four. in addition we show that the collective continues to perform well in the presence of high noise levels and when the environment is highly dynamic. More notably, in the presence of a larger number of rovers or rovers with noisy sensors, the improvements due to the proposed method become significantly more pronounced.

  9. Implications of mercury and lead concentrations on breeding physiology and phenology in an Arctic bird.

    PubMed

    Provencher, J F; Forbes, M R; Hennin, H L; Love, O P; Braune, B M; Mallory, M L; Gilchrist, H G

    2016-11-01

    Although physiological traits and phenology are thought to be evolved traits, they often show marked variation within populations, which may be related to extrinsic factors. For example, trace elements such as mercury (Hg) and lead (Pb) alter biochemical processes within wildlife that may affect migration and breeding. While there is a growing understanding of how contaminants may influence wildlife physiology, studies addressing these interactions in free-living species are still limited. We examined how four non-essential trace elements (cadmium, Hg, Pb and selenium) interacted with physiological and breeding measures known to influence breeding in a free-living population of common eider ducks (Somateria mollissima). We collected blood from female eiders as they arrived at a breeding colony in northern Canada. Blood was subsequently assessed for baseline corticosterone (CORT), immunoglobulin Y (IgY), and the four trace elements. We used model selection to identify which elements varied most with CORT, IgY, arrival condition, and arrival timing. We then used path analysis to assess how the top two elements from the model selection process (Hg and Pb) varied with metrics known to influence reproduction. We found that arrival date, blood Hg, CORT, and IgY showed significant inter-annual variation. While blood Pb concentrations were low, blood Pb levels significantly increased with later arrival date of the birds, and varied negatively with eider body condition, suggesting that even at low blood concentrations, Pb may be related to lower investment in reproduction in eiders. In contrast, blood Hg concentrations were positively correlated with eider body condition, indicating that fatter birds also had higher Hg burdens. Overall, our results suggest that although blood Hg and Pb concentrations were below no-effect levels, these low level concentrations of known toxic metals show significant relationships with breeding onset and condition in female eider ducks

  10. Dietary Variation and Evolution of Gene Copy Number among Dog Breeds

    PubMed Central

    Reiter, Taylor; Jagoda, Evelyn; Capellini, Terence D.

    2016-01-01

    Prolonged human interactions and artificial selection have influenced the genotypic and phenotypic diversity among dog breeds. Because humans and dogs occupy diverse habitats, ecological contexts have likely contributed to breed-specific positive selection. Prior to the advent of modern dog-feeding practices, there was likely substantial variation in dietary landscapes among disparate dog breeds. As such, we investigated one type of genetic variant, copy number variation, in three metabolic genes: glucokinase regulatory protein (GCKR), phytanol-CoA 2-hydroxylase (PHYH), and pancreatic α-amylase 2B (AMY2B). These genes code for proteins that are responsible for metabolizing dietary products that originate from distinctly different food types: sugar, meat, and starch, respectively. After surveying copy number variation among dogs with diverse dietary histories, we found no correlation between diet and positive selection in either GCKR or PHYH. Although it has been previously demonstrated that dogs experienced a copy number increase in AMY2B relative to wolves during or after the dog domestication process, we demonstrate that positive selection continued to act on amylase copy number in dog breeds that consumed starch-rich diets in time periods after domestication. Furthermore, we found that introgression with wolves is not responsible for deterioration of positive selection on AMY2B among diverse dog breeds. Together, this supports the hypothesis that the amylase copy number expansion is found universally in dogs. PMID:26863414

  11. Dietary Variation and Evolution of Gene Copy Number among Dog Breeds.

    PubMed

    Reiter, Taylor; Jagoda, Evelyn; Capellini, Terence D

    2016-01-01

    Prolonged human interactions and artificial selection have influenced the genotypic and phenotypic diversity among dog breeds. Because humans and dogs occupy diverse habitats, ecological contexts have likely contributed to breed-specific positive selection. Prior to the advent of modern dog-feeding practices, there was likely substantial variation in dietary landscapes among disparate dog breeds. As such, we investigated one type of genetic variant, copy number variation, in three metabolic genes: glucokinase regulatory protein (GCKR), phytanol-CoA 2-hydroxylase (PHYH), and pancreatic α-amylase 2B (AMY2B). These genes code for proteins that are responsible for metabolizing dietary products that originate from distinctly different food types: sugar, meat, and starch, respectively. After surveying copy number variation among dogs with diverse dietary histories, we found no correlation between diet and positive selection in either GCKR or PHYH. Although it has been previously demonstrated that dogs experienced a copy number increase in AMY2B relative to wolves during or after the dog domestication process, we demonstrate that positive selection continued to act on amylase copy number in dog breeds that consumed starch-rich diets in time periods after domestication. Furthermore, we found that introgression with wolves is not responsible for deterioration of positive selection on AMY2B among diverse dog breeds. Together, this supports the hypothesis that the amylase copy number expansion is found universally in dogs.

  12. Phylogeography of a migratory songbird across its Canadian breeding range: Implications for conservation units.

    PubMed

    Haché, Samuel; Bayne, Erin M; Villard, Marc-André; Proctor, Heather; Davis, Corey S; Stralberg, Diana; Janes, Jasmine K; Hallworth, Michael T; Foster, Kenneth R; Chidambara-Vasi, Easwaramurthyvasi; Grossi, Alexandra A; Gorrell, Jamieson C; Krikun, Richard

    2017-08-01

    The objectives of this study were to describe and evaluate potential drivers of genetic structure in Canadian breeding populations of the Ovenbird, Seiurus aurocapilla. We performed genetic analyses on feather samples of individuals from six study sites using nuclear microsatellites. We also assessed species identity and population genetic structure of quill mites (Acariformes, Syringophilidae). For male Ovenbirds breeding in three study sites, we collected light-level geolocator data to document migratory paths and identify the wintering grounds. We also generated paleohindcast projections from bioclimatic models of Ovenbird distribution to identify potential refugia during the last glacial maximum (LGM, 21,000 years before present) as a factor explaining population genetic structure. Birds breeding in the Cypress Hills (Alberta/Saskatchewan) may be considered a distinct genetic unit, but there was no evidence for genetic differentiation among any other populations. We found relatively strong migratory connectivity in both western and eastern populations, but some evidence of mixing among populations on the wintering grounds. There was also little genetic variation among syringophilid mites from the different Ovenbird populations. These results are consistent with paleohindcast distribution predictions derived from two different global climate models indicating a continuous single LGM refugium, with the possibility of two refugia. Our results suggest that Ovenbird populations breeding in boreal and hemiboreal regions are panmictic, whereas the population breeding in Cypress Hills should be considered a distinct management unit.

  13. Necrotizing meningoencephalitis in a large mixed-breed dog.

    PubMed

    Estey, Chelsie M; Scott, Steven J; Cerda-Gonzalez, Sofia

    2014-12-01

    A 4-year-old 26-kg (57.2-lb) spayed female Staffordshire Bull Terrier mix was evaluated because of a 24-hour history of cluster seizures. Neurologic examination revealed altered mentation and multifocal intracranial signs; MRI was performed. The MRI findings included multifocal, asymmetric forebrain lesions affecting both the gray and white matter, an area suggestive of focal necrosis, and loss of corticomedullary distinction. A midline shift and caudal transtentorial herniation were noted, suggestive of greater than normal intracranial pressure. Because the dog's clinical signs worsened despite medical treatment and additional evidence of increased intracranial pressure, bilateral craniectomy and durectomy were performed. Histologic evaluation of a brain biopsy specimen revealed bilateral and asymmetric areas of necrosis in the subcortical white matter and adjacent gray matter. At the periphery of the necrotic areas, there was increased expression of glial fibrillary acidic protein and Virchow-Robin spaces were expanded by CD3+ lymphocytes. Results of immunohistochemical analysis of brain tissue were negative for canine distemper virus, Neospora canis, and Toxoplasma gondii. These clinical, imaging, and histopathologic findings were compatible with necrotizing meningoencephalitis. The dog's neurologic status continued to worsen following surgery. Repeated MRI revealed ongoing signs of increased intracranial pressure, despite the bilateral craniectomy. The owners elected euthanasia. To the author's knowledge, this is the first report of necrotizing meningoencephalitis in a large mixed-breed dog. Necrotizing meningoencephalitis should be considered as a differential diagnosis in dogs other than small or toy breeds that have signs suggestive of inflammatory disease.

  14. Rapid cyling plant breeding in citrus

    USDA-ARS?s Scientific Manuscript database

    Resistance or tolerance to huanglongbing (HLB) and other important traits have been identified in several citrus types and relatives and associated markers should be identified soon. What is urgently needed in addition is an accelerated strategy for citrus variety breeding. Identification and use of...

  15. A New Breed of Environmental Film

    ERIC Educational Resources Information Center

    Malamud, Randy

    2008-01-01

    In this article, the author reports how today's environmental film festivals feature a new breed of documentary that offer nuanced narratives about intricate technologies. The author relates that the environmental films he grew up with sedately depicted the quiet sublimity of the wilderness. Today's films, the author observes, aim far beyond a…

  16. New Brahman breed improvement program at STARS

    USDA-ARS?s Scientific Manuscript database

    At the USDA, ARS, Subtropical Agricultural Research Station (STARS) in Brooksville, Florida we have initiated a new ambitious research project that many believe will have a positive influence on the Brahman breed. This research was developed from a meeting held at STARS that included past and prese...

  17. Traditional breeding and cultivar development (potato)

    USDA-ARS?s Scientific Manuscript database

    Traditional breeding allows for the genetic ‘reshuffling’ of genes and their recombination into new genotypes that may carry the desired assemblage of resistance and agronomic traits necessary for release as a new cultivar. While molecular biology techniques can be useful for improving upon a weakne...

  18. Breeding red-winged blackbirds in captivity

    USGS Publications Warehouse

    Know, C.J.; Stickley, A.R.

    1974-01-01

    Ability to establish and maintain self-sustaining breeding colonies of captive Red-winged Blackbirds (Agelaius phoeniceus) would facilitate long-term studies designed to develop methods for alleviating blackbird depredations as well as provide basic life history data. To be most useful, the colonies should be established in pens near laboratory facilities; this frequently involves putting colonies in unnatural nesting habitat. This paper describes a 5-year effort at Gainesville, Florida, to induce captive Red-wings, most of them taken from the wild as nestlings and then hand-reared in our laboratory, to breed regularly under such conditions. Except for an undocumented report of two young fully reared at the London Zoo in 1913 (Prestwick per. comm.), captive Red-wings have not been induced to breed successfully under avicultural conditions. In 1969, captive Red-wings, wild-trapped as adults, were induced to breed and to rear young successfully in large pens over normal marsh and hayfield nesting habitat in Ohio (Jackson pers. comm.). Earlier, a pair of Red-wings that had been caught as adults and kept together for a year hatched two young in a 40- X 20- X 6-foot cage in Massachusetts (Wetherbee 1960, Wilson Bull. 74: 90), but the nestlings died soon after hatching.

  19. Recent advances in peanut breeding and genetics

    USDA-ARS?s Scientific Manuscript database

    Most previous advances in peanut cultivar development have been made using conventional breeding methods for self-pollinated crops. Peanut has lagged behind many other crops on use of molecular genetic technology for cultivar development in part due to lack of investment, but also because of low le...

  20. Breeding for phytonutrient content; examples from watermelon

    USDA-ARS?s Scientific Manuscript database

    Breeding for high phytonutrient fruits and vegetables can be a fairly straightforward endeavor when the compounds of interest produce a visible effect or the methods for quantifying the compounds simple and inexpensive. Lycopene in tomatoes and watermelon is one such compound, since the amount of r...

  1. Linkage Drag: Implication for Plant Breeding

    USDA-ARS?s Scientific Manuscript database

    Linkage drag is commonly observed in plant breeding, yet the molecular mechanisms controlling this is unclear. The Pi-ta gene, a single copy gene near the centromere region of chromosome 12, confers resistance to races of Magnaporthe oryzae that contain AVR-Pita. The Pi-ta gene in Tetep has been su...

  2. Genomics to feed a switchgrass breeding program

    USDA-ARS?s Scientific Manuscript database

    Development of improved cultivars is one of three pillars, along with sustainable production and efficient conversion, required for dedicated cellulosic bioenergy crops to succeed. Breeding new cultivars is a long, slow process requiring patience, dedication, and motivation to realize gains and adva...

  3. Impacts of the basic breeding program

    USDA-ARS?s Scientific Manuscript database

    The USDAs basic sugarcane breeding program began in the mid 1950s with the objective of moving genes from wild sugarcane germplasm into commercial cane. Several releases have been made from this program, but it is a very long process. To date, the pedigree of seven commercial Louisiana varieties ca...

  4. Wheat breeding for quality: an historical review

    USDA-ARS?s Scientific Manuscript database

    Wheat (Triticum spp. L.) is a leading cereal contributing to the nourishment of humankind. Since its domestication ca. 12 000 years ago, humans have profoundly influenced its evolution. In the more recent past, breeding via cross-hybridization and the selection of progeny with superior end-use quali...

  5. Combination solar hothouse and silkworm breeding house

    SciTech Connect

    Vardiashvili, A.B.; Muradov, M.; Kim, V.D.

    1980-01-01

    The basic arrangement is shown for a combination silkworm breeding house and solar hothouse with subsoil irrigation and accumulation of heat; it employs a semicylindrical film covering. The process of accumulation of solar heat in the subsoil pebble stores, in water-heater banks, and in the soil is described.

  6. Validating selective breeding approaches for disease resistance

    USDA-ARS?s Scientific Manuscript database

    Selective breeding of rainbow trout at the USDA/ARS National Center for Cool and Cold Water Aquaculture (NCCCWA) in Leetown, West Virginia is designed to accomplish four goals: 1) define commercially important traits such as disease resistance, growth rate, stress response, and feed efficiency; 2) d...

  7. Mary Bidwell Breed: The Educator as Dean.

    ERIC Educational Resources Information Center

    Fley, Jo Ann; Jaramillo, George R.

    1979-01-01

    Mary Bidwell Breed predicted that midwestern universities would probably "pass through a stage of educational development in which the liberal arts are entirely feminized, the men are entirely commercialized." We can appreciate how close she came to pinpointing trends which did not begin to be reversed until sixty years later.…

  8. Breeding lettuce for fresh-cut processing

    USDA-ARS?s Scientific Manuscript database

    Lettuce is increasingly consumed in fresh-cut packaged salads. New cultivars specifically bred for this use can enhance production and processing efficiency and extend shelf life. Cultivars with novel head architectures and leaf traits are being released by private and public breeding programs with ...

  9. Breeding System of Ruellia succulenta Small (Acanthaceae)

    USDA-ARS?s Scientific Manuscript database

    This study examines the breeding system of Ruellia succulenta (Acanthaceae), an herbaceous perennial found in the pine rockland habitat of southern Florida. Hand pollination treatments were performed on 75 plants, 25 from each of three sites. Treatments applied to test plants included: 1) control ...

  10. Marketing Potential of Advanced Breeding Clones

    USDA-ARS?s Scientific Manuscript database

    The accumulation of reducing sugars during cold storage of potato tubers is a serious and costly problem for producers and processors. The degree to which cultivars accumulate reducing sugars during storage determines their processing and market potential. Cultivars or advanced breeding lines with...

  11. Marketing potential of advanced breeding clones

    USDA-ARS?s Scientific Manuscript database

    The accumulation of reducing sugars during cold storage of potato tubers is a serious and costly problem for producers and processors. The degree to which cultivars accumulate reducing sugars during storage determines their processing and market potential. Cultivars or advanced breeding lines with...

  12. Founding concepts for tree breeding and research

    Treesearch

    Hyun Kang

    1983-01-01

    Forestry research is a multidisciplinary venture and is typically a long-term effort with relatively low funding. The success of forestry research and tree breeding depends greatly on the coordination among forestry practitioners, research managers, and researchers. To coordinate they must have a common understanding of the research process. Therefore, the common...

  13. Breed differences in behavioural development in kittens.

    PubMed

    Marchei, P; Diverio, S; Falocci, N; Fatjó, J; Ruiz-de-la-Torre, J L; Manteca, X

    2009-03-23

    Differences in behaviour of pure breed cats have been suggested but not wholly investigated. Oriental/Siamese/Abyssinian (OSA) kittens (n=43) were weekly compared with Norwegian Forest (NFO) kittens (n=39) from the 4th to the 10th week of age in a repeated Open Field Test (OFT) paradigm. Heart rate (HR) and rectal temperature (RT) before and after the test, and behavioural responses during the OFT were recorded. Behaviours registered were analysed by focal animal sampling. Significant breed differences were found; cats of the northern zones (NFO) seem to develop earlier thermoregulatory abilities. Precocious opening of eyes, higher locomotion scores and longer time spent standing, observed in OSA kittens may indicate an earlier neurological development. Inter breed differences recorded for exploration and locomotion seem to indicate coping style divergences: in the OFT challenging situation OSA kittens presented higher emotional tachycardia and performed more passively, with a faster decline in exploration and locomotion scores. NFO kittens exerted a more active behaviour as they spent more time exploring the arena and in escape attempts. Notwithstanding OSA and NFO cat selection was mainly aimed to improve divergent morphological traits, some different behavioural and physiological traits seem to have been maintained or co-selected within each breed.

  14. Impacts of the basic breeding program

    USDA-ARS?s Scientific Manuscript database

    The USDAs basic sugarcane breeding program began in the mid 1950s with the objective of moving genes from wild sugarcane germplasm into commercial cane. Several releases have been made from this program, but it is a very long process. To date, the pedigree of seven commercial Louisiana varieties ca...

  15. Impacts of the USDA basic breeding program

    USDA-ARS?s Scientific Manuscript database

    The USDAs basic sugarcane breeding program began in the mid 1950s with the objective of moving genes from wild sugarcane germplasm into commercial cane. Several releases have been made from this program, but it is a very long process. To date, the pedigree of seven commercial Louisiana varieties can...

  16. A brief genomic history of tomato breeding

    USDA-ARS?s Scientific Manuscript database

    Here we report a brief genomic history of tomato breeding by analyzing the genomes of 360 diverse accessions collected all over the world. These included 333 accessions from the red fruited clade (S. pimpinellifolium, S. l. var. cerasiforme, and S. lycopersicum) that represent various geographical o...

  17. Genetic distance and species formation in evolving populations.

    PubMed

    Higgs, P G; Derrida, B

    1992-11-01

    We compare the behavior of the genetic distance between individuals in evolving populations for three stochastic models. In the first model reproduction is asexual and the distribution of genetic distances reflects the genealogical tree of the population. This distribution fluctuates greatly in time, even for very large populations. In the second model reproduction is sexual with random mating allowed between any pair of individuals. In this case, the population becomes homogeneous and the genetic distance between pairs of individuals has small fluctuations which vanish in the limit of an infinitely large population. In the third model reproduction is still sexual but instead of random mating, mating only occurs between individuals which are genetically similar to each other. In that case, the population splits spontaneously into species which are in reproductive isolation from one another and one observes a steady state with a continual appearance and extinction of species in the population. We discuss this model in relation to the biological theory of speciation and isolating mechanisms. We also point out similarities between these three models of evolving populations and the theory of disordered systems in physics.

  18. Structural Analysis of an Evolved Transketolase Reveals Divergent Binding Modes.

    PubMed

    Affaticati, Pierre E; Dai, Shao-Bo; Payongsri, Panwajee; Hailes, Helen C; Tittmann, Kai; Dalby, Paul A

    2016-10-21

    The S385Y/D469T/R520Q variant of E. coli transketolase was evolved previously with three successive smart libraries, each guided by different structural, bioinformatical or computational methods. Substrate-walking progressively shifted the target acceptor substrate from phosphorylated aldehydes, towards a non-phosphorylated polar aldehyde, a non-polar aliphatic aldehyde, and finally a non-polar aromatic aldehyde. Kinetic evaluations on three benzaldehyde derivatives, suggested that their active-site binding was differentially sensitive to the S385Y mutation. Docking into mutants generated in silico from the wild-type crystal structure was not wholly satisfactory, as errors accumulated with successive mutations, and hampered further smart-library designs. Here we report the crystal structure of the S385Y/D469T/R520Q variant, and molecular docking of three substrates. This now supports our original hypothesis that directed-evolution had generated an evolutionary intermediate with divergent binding modes for the three aromatic aldehydes tested. The new active site contained two binding pockets supporting π-π stacking interactions, sterically separated by the D469T mutation. While 3-formylbenzoic acid (3-FBA) preferred one pocket, and 4-FBA the other, the less well-accepted substrate 3-hydroxybenzaldehyde (3-HBA) was caught in limbo with equal preference for the two pockets. This work highlights the value of obtaining crystal structures of evolved enzyme variants, for continued and reliable use of smart library strategies.

  19. Evolving mobile robots in simulated and real environments.

    PubMed

    Miglino, O; Lund, H H; Nolfi, S

    1995-01-01

    The problem of the validity of simulation is particularly relevant for methodologies that use machine learning techniques to develop control systems for autonomous robots, as, for instance, the artificial life approach known as evolutionary robotics. In fact, although it has been demonstrated that training or evolving robots in real environments is possible, the number of trials needed to test the system discourages the use of physical robots during the training period. By evolving neural controllers for a Khepera robot in computer simulations and then transferring the agents obtained to the real environment we show that (a) an accurate model of a particular robot-environment dynamics can be built by sampling the real world through the sensors and the actuators of the robot; (b) the performance gap between the obtained behaviors in simulated and real environments may be significantly reduced by introducing a "conservative" form of noise; (c) if a decrease in performance is observed when the system is transferred to a real environment, successful and robust results can be obtained by continuing the evolutionary process in the real environment for a few generations.

  20. Virtual Nursing Avatars: Nurse Roles and Evolving Concepts of Care

    PubMed

    Abbott, Miriam Bowers; Shaw, Peggy

    2016-08-15

    Advances in computer software have provided interactive tools that perform many of the duties once in the domain of the nursing profession. Sometimes referred to as 'virtual nursing avatars,' the duties delegated to this technology include facilitating check-ins for patients and coaching patients as they make lifestyle changes. Researchers continue to develop computer applications for virtual nurse avatars. As computers and smartphones take on tasks once in the domain of humans, the roles of nurses will evolve. The arc of this evolution will be determined by the limits of technology, evolving concepts of care, and changing population needs. In this article, the authors share examples of nursing avatar applications, discuss concerns about virtual nurse avatars, reinforce nursing as a caring profession, present avatars as caring agents, and consider the future of nursing avatars. They conclude that, although virtual nurse avatars can perform some nursing tasks in an acceptable manner, they are limited in their ability to make complex judgments and engage in collaboration.

  1. An evolvable space telescope for future astronomical missions

    NASA Astrophysics Data System (ADS)

    Polidan, Ronald S.; Breckinridge, James B.; Lillie, Charles F.; MacEwen, Howard A.; Flannery, Martin R.; Dailey, Dean R.

    2014-08-01

    Astronomical flagship missions after JWST will require affordable space telescopes and science instruments. Innovative spacecraft-electro-opto-mechanical system architectures matched to the science requirements are needed for observations for exoplanet characterization, cosmology, dark energy, galactic evolution formation of stars and planets, and many other research areas. The needs and requirements to perform this science will continue to drive us toward larger and larger apertures. Recent technology developments in precision station keeping of spacecraft, interplanetary transfer orbits, wavefront/sensing and control, laser engineering, macroscopic application of nano-technology, lossless optical designs, deployed structures, thermal management, interferometry, detectors and signal processing enable innovative telescope/system architectures with break-through performance. Unfortunately, NASA's budget for Astrophysics is unlikely to be able to support the funding required for the 8 m to 16 m telescopes that have been studied as a follow-on to JWST using similar development/assembly approaches without decimating the rest of the Astrophysics Division's budget. Consequently, we have been examining the feasibility of developing an "Evolvable Space Telescope" that would begin as a 3 to 4 m telescope when placed on orbit and then periodically be augmented with additional mirror segments, structures, and newer instruments to evolve the telescope and achieve the performance of a 16 m or larger space telescope. This paper reviews the approach for such a mission and identifies and discusses candidate architectures.

  2. An Evolvable Space Telescope for Future Astronomical Missions

    NASA Astrophysics Data System (ADS)

    Polidan, Ronald S.; Breckinridge, James B.; Lillie, Charles F.; MacEwen, Howard A.; Flannery, Martin; Dailey, Dean

    2015-01-01

    Astronomical flagship missions after the James Webb Space Telescope (JWST) will require lower cost space telescopes and science instruments. Innovative spacecraft-electro-opto-mechanical system architectures matched to the science requirements are needed for observations for exoplanet characterization, cosmology, dark energy, galactic evolution formation of stars and planets, and many other research areas. The needs and requirements to perform this science will continue to drive us toward larger and larger apertures.Recent technology developments in precision station keeping of spacecraft, interplanetary transfer orbits, wavefront/sensing and control, laser engineering, macroscopic application of nano-technology, lossless optical designs, deployed structures, thermal management, interferometry, detectors and signal processing enable innovative telescope/system architectures with break-through performance.Unfortunately, NASA's budget for Astrophysics is unlikely to be able to support the funding required for the 8-m to 16-m telescopes that have been studied for the follow-on to JWST using similar development/assembly approaches without accounting for too large of a portion of the Astrophysics Division's budget. Consequently, we have been examining the feasibility of developing an 'Evolvable Space Telescope' that would be 3 to 4-m when placed on orbit and then periodically augmented with additional mirror segments, structures, and newer instruments to evolve the telescope and achieve the performance of a 16-m space telescope.This paper reviews the technologies required for such a mission, identifies candidate architectures, and discusses different science measurement objectives for these architectures.

  3. Structural Analysis of an Evolved Transketolase Reveals Divergent Binding Modes

    PubMed Central

    Affaticati, Pierre E.; Dai, Shao-Bo; Payongsri, Panwajee; Hailes, Helen C.; Tittmann, Kai; Dalby, Paul A.

    2016-01-01

    The S385Y/D469T/R520Q variant of E. coli transketolase was evolved previously with three successive smart libraries, each guided by different structural, bioinformatical or computational methods. Substrate-walking progressively shifted the target acceptor substrate from phosphorylated aldehydes, towards a non-phosphorylated polar aldehyde, a non-polar aliphatic aldehyde, and finally a non-polar aromatic aldehyde. Kinetic evaluations on three benzaldehyde derivatives, suggested that their active-site binding was differentially sensitive to the S385Y mutation. Docking into mutants generated in silico from the wild-type crystal structure was not wholly satisfactory, as errors accumulated with successive mutations, and hampered further smart-library designs. Here we report the crystal structure of the S385Y/D469T/R520Q variant, and molecular docking of three substrates. This now supports our original hypothesis that directed-evolution had generated an evolutionary intermediate with divergent binding modes for the three aromatic aldehydes tested. The new active site contained two binding pockets supporting π-π stacking interactions, sterically separated by the D469T mutation. While 3-formylbenzoic acid (3-FBA) preferred one pocket, and 4-FBA the other, the less well-accepted substrate 3-hydroxybenzaldehyde (3-HBA) was caught in limbo with equal preference for the two pockets. This work highlights the value of obtaining crystal structures of evolved enzyme variants, for continued and reliable use of smart library strategies. PMID:27767080

  4. Development and application of biological technologies in fish genetic breeding.

    PubMed

    Xu, Kang; Duan, Wei; Xiao, Jun; Tao, Min; Zhang, Chun; Liu, Yun; Liu, ShaoJun

    2015-02-01

    Fish genetic breeding is a process that remolds heritable traits to obtain neotype and improved varieties. For the purpose of genetic improvement, researchers can select for desirable genetic traits, integrate a suite of traits from different donors, or alter the innate genetic traits of a species. These improved varieties have, in many cases, facilitated the development of the aquaculture industry by lowering costs and increasing both quality and yield. In this review, we present the pertinent literatures and summarize the biological bases and application of selection breeding technologies (containing traditional selective breeding, molecular marker-assisted breeding, genome-wide selective breeding and breeding by controlling single-sex groups), integration breeding technologies (containing cross breeding, nuclear transplantation, germline stem cells and germ cells transplantation, artificial gynogenesis, artificial androgenesis and polyploid breeding) and modification breeding technologies (represented by transgenic breeding) in fish genetic breeding. Additionally, we discuss the progress our laboratory has made in the field of chromosomal ploidy breeding of fish, including distant hybridization, gynogenesis, and androgenesis. Finally, we systematically summarize the research status and known problems associated with each technology.

  5. Relationships among and variation within rare breeds of swine.

    PubMed

    Roberts, K S; Lamberson, W R

    2015-08-01

    Extinction of rare breeds of livestock threatens to reduce the total genetic variation available for selection in the face of the changing environment and new diseases. Swine breeds facing extinction typically share characteristics such as small size, slow growth rate, and high fat percentage, which limit them from contributing to commercial production. Compounding the risk of loss of variation is the lack of pedigree information for many rare breeds due to inadequate herd books, which increases the chance that producers are breeding closely related individuals. By making genetic data available, producers can make more educated breeding decisions to preserve genetic diversity in future generations, and conservation organizations can prioritize investments in breed preservation. The objective of this study was to characterize genetic variation within and among breeds of swine and prioritize heritage breeds for preservation. Genotypes from the Illumina PorcineSNP60 BeadChip (GeneSeek, Lincoln, NE) were obtained for Guinea, Ossabaw Island, Red Wattle, American Saddleback, Mulefoot, British Saddleback, Duroc, Landrace, Large White, Pietrain, and Tamworth pigs. A whole-genome analysis toolset was used to construct a genomic relationship matrix and to calculate inbreeding coefficients for the animals within each breed. Relatedness and average inbreeding coefficient differed among breeds, and pigs from rare breeds were generally more closely related and more inbred ( < 0.05). A multidimensional scaling diagram was constructed based on the SNP genotypes. Animals within breeds clustered tightly together except for 2 Guinea pigs. Tamworth, Duroc, and Mulefoot tended to not cluster with the other 7 breeds.

  6. Possible mechanisms of host resistance to Haemonchus contortus infection in sheep breeds native to the Canary Islands

    PubMed Central

    Guo, Zhengyu; González, Jorge Francisco; Hernandez, Julia N.; McNeilly, Tom N.; Corripio-Miyar, Yolanda; Frew, David; Morrison, Tyler; Yu, Peng; Li, Robert W.

    2016-01-01

    Haemonchus contortus appears to be the most economically important helminth parasite for small ruminant production in many regions of the world. The two sheep breeds native to the Canary Islands display distinctly different resistant phenotypes under both natural and experimental infections. Canaria Hair Breed (CHB) tends to have significantly lower worm burden and delayed and reduced egg production than the susceptible Canaria Sheep (CS). To understand molecular mechanisms underlying host resistance, we compared the abomasal mucosal transcriptome of the two breeds in response to Haemonchus infection using RNAseq technology. The transcript abundance of 711 and 50 genes were significantly impacted by infection in CHB and CS, respectively (false discovery rate <0.05) while 27 of these genes were significantly affected in both breeds. Likewise, 477 and 16 Gene Ontology (GO) terms were significantly enriched in CHB and CS, respectively (P < 1.0 × 10−4). A broad range of mechanisms have evolved in resistant CHB to provide protection against the parasite. Our findings suggest that readily inducible acute inflammatory responses, complement activation, accelerated cell proliferation and subsequent tissue repair, and immunity directed against parasite fecundity all contributed to the development of host resistance to parasitic infection in the resistant breed. PMID:27197554

  7. Breeding productivity of Smith Island black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Jorde, Dennis G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.; Perry, M.C.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  8. Application of Genomic Tools in Plant Breeding

    PubMed Central

    Pérez-de-Castro, A.M.; Vilanova, S.; Cañizares, J.; Pascual, L.; Blanca, J.M.; Díez, M.J.; Prohens, J.; Picó, B.

    2012-01-01

    Plant breeding has been very successful in developing improved varieties using conventional tools and methodologies. Nowadays, the availability of genomic tools and resources is leading to a new revolution of plant breeding, as they facilitate the study of the genotype and its relationship with the phenotype, in particular for complex traits. Next Generation Sequencing (NGS) technologies are allowing the mass sequencing of genomes and transcriptomes, which is producing a vast array of genomic information. The analysis of NGS data by means of bioinformatics developments allows discovering new genes and regulatory sequences and their positions, and makes available large collections of molecular markers. Genome-wide expression studies provide breeders with an understanding of the molecular basis of complex traits. Genomic approaches include TILLING and EcoTILLING, which make possible to screen mutant and germplasm collections for allelic variants in target genes. Re-sequencing of genomes is very useful for the genome-wide discovery of markers amenable for high-throughput genotyping platforms, like SSRs and SNPs, or the construction of high density genetic maps. All these tools and resources facilitate studying the genetic diversity, which is important for germplasm management, enhancement and use. Also, they allow the identification of markers linked to genes and QTLs, using a diversity of techniques like bulked segregant analysis (BSA), fine genetic mapping, or association mapping. These new markers are used for marker assisted selection, including marker assisted backcross selection, ‘breeding by design’, or new strategies, like genomic selection. In conclusion, advances in genomics are providing breeders with new tools and methodologies that allow a great leap forward in plant breeding, including the ‘superdomestication’ of crops and the genetic dissection and breeding for complex traits. PMID:23115520

  9. Evolvability Is an Evolved Ability: The Coding Concept as the Arch-Unit of Natural Selection.

    PubMed

    Janković, Srdja; Ćirković, Milan M

    2016-03-01

    Physical processes that characterize living matter are qualitatively distinct in that they involve encoding and transfer of specific types of information. Such information plays an active part in the control of events that are ultimately linked to the capacity of the system to persist and multiply. This algorithmicity of life is a key prerequisite for its Darwinian evolution, driven by natural selection acting upon stochastically arising variations of the encoded information. The concept of evolvability attempts to define the total capacity of a system to evolve new encoded traits under appropriate conditions, i.e., the accessible section of total morphological space. Since this is dependent on previously evolved regulatory networks that govern information flow in the system, evolvability itself may be regarded as an evolved ability. The way information is physically written, read and modified in living cells (the "coding concept") has not changed substantially during the whole history of the Earth's biosphere. This biosphere, be it alone or one of many, is, accordingly, itself a product of natural selection, since the overall evolvability conferred by its coding concept (nucleic acids as information carriers with the "rulebook of meanings" provided by codons, as well as all the subsystems that regulate various conditional information-reading modes) certainly played a key role in enabling this biosphere to survive up to the present, through alterations of planetary conditions, including at least five catastrophic events linked to major mass extinctions. We submit that, whatever the actual prebiotic physical and chemical processes may have been on our home planet, or may, in principle, occur at some time and place in the Universe, a particular coding concept, with its respective potential to give rise to a biosphere, or class of biospheres, of a certain evolvability, may itself be regarded as a unit (indeed the arch-unit) of natural selection.

  10. Evolvability Is an Evolved Ability: The Coding Concept as the Arch-Unit of Natural Selection

    NASA Astrophysics Data System (ADS)

    Janković, Srdja; Ćirković, Milan M.

    2016-03-01

    Physical processes that characterize living matter are qualitatively distinct in that they involve encoding and transfer of specific types of information. Such information plays an active part in the control of events that are ultimately linked to the capacity of the system to persist and multiply. This algorithmicity of life is a key prerequisite for its Darwinian evolution, driven by natural selection acting upon stochastically arising variations of the encoded information. The concept of evolvability attempts to define the total capacity of a system to evolve new encoded traits under appropriate conditions, i.e., the accessible section of total morphological space. Since this is dependent on previously evolved regulatory networks that govern information flow in the system, evolvability itself may be regarded as an evolved ability. The way information is physically written, read and modified in living cells (the "coding concept") has not changed substantially during the whole history of the Earth's biosphere. This biosphere, be it alone or one of many, is, accordingly, itself a product of natural selection, since the overall evolvability conferred by its coding concept (nucleic acids as information carriers with the "rulebook of meanings" provided by codons, as well as all the subsystems that regulate various conditional information-reading modes) certainly played a key role in enabling this biosphere to survive up to the present, through alterations of planetary conditions, including at least five catastrophic events linked to major mass extinctions. We submit that, whatever the actual prebiotic physical and chemical processes may have been on our home planet, or may, in principle, occur at some time and place in the Universe, a particular coding concept, with its respective potential to give rise to a biosphere, or class of biospheres, of a certain evolvability, may itself be regarded as a unit (indeed the arch-unit) of natural selection.

  11. Selective Attention and Control of Action: Comparative Psychology of an Artificial, Evolved Agent and People

    ERIC Educational Resources Information Center

    Ward, Robert; Ward, Ronnie

    2008-01-01

    This study examined the selective attention abilities of a simple, artificial, evolved agent and considered implications of the agent's performance for theories of selective attention and action. The agent processed two targets in continuous time, catching one and then the other. This task required many cognitive operations, including prioritizing…

  12. Dental Therapy: Evolving in Minnesota’s Safety Net

    PubMed Central

    Born, David; Nagy, Amanda

    2014-01-01

    Objectives. We identified Minnesota’s initial dental therapy employers and surveyed dental safety net providers’ perceptions of dental therapy. Methods. In July 2011, we surveyed 32 Minnesota dental safety net providers to assess their prospective views on dental therapy employment options. In October 2013, we used an employment scan to reveal characteristics of the early adopters of dental therapy. Results. Before the availability of licensed dental therapists, safety net dental clinic directors overwhelmingly (77%) supported dental therapy. As dental therapists have become licensed over the past 2 years, the early employers of dental therapists are safety net clinics. Conclusions. Although the concept of dental therapy remains controversial in Minnesota, it now has a firm foundation in the state’s safety net clinics. Dental therapists are being used in innovative and diverse ways, so, as dental therapy continues to evolve, further research to identify best practices for incorporating dental therapists into the oral health care team is needed. PMID:24825234

  13. The evolving role of radiation therapy in pediatric Hodgkin's disease.

    PubMed

    Fredman, Elisha; Mansur, David B; Russo, Suzanne

    2016-06-01

    Identifying the optimal treatment of pediatric Hodgkin's disease has been at the forefront of clinical investigation in recent years. Results of a number of large clinical trials have driven paradigm shifts in how physicians approach this often curable disease. In an effort to balance the goals of maximizing survival while minimizing acute toxicities and late complications, the recommended indications, targets, doses and schedules of chemotherapy and radiation have and continue to evolve. Recent attempts to decrease the total volume of tissue receiving radiation without requiring a significant escalation in cytotoxic chemotherapy have shown promise in low, intermediate and high risk patients. Utilizing risk-adapted, response-based treatment, researchers hope to uncover a subpopulation that may not require previously considered standard treatment modalities.

  14. Smart signal processing for an evolving electric grid

    NASA Astrophysics Data System (ADS)

    Silva, Leandro Rodrigues Manso; Duque, Calos Augusto; Ribeiro, Paulo F.

    2015-12-01

    Electric grids are interconnected complex systems consisting of generation, transmission, distribution, and active loads, recently called prosumers as they produce and consume electric energy. Additionally, these encompass a vast array of equipment such as machines, power transformers, capacitor banks, power electronic devices, motors, etc. that are continuously evolving in their demand characteristics. Given these conditions, signal processing is becoming an essential assessment tool to enable the engineer and researcher to understand, plan, design, and operate the complex and smart electronic grid of the future. This paper focuses on recent developments associated with signal processing applied to power system analysis in terms of characterization and diagnostics. The following techniques are reviewed and their characteristics and applications discussed: active power system monitoring, sparse representation of power system signal, real-time resampling, and time-frequency (i.e., wavelets) applied to power fluctuations.

  15. Malaria genomics: tracking a diverse and evolving parasite population.

    PubMed

    Kwiatkowski, Dominic

    2015-03-01

    Malaria parasites are continually evolving to evade the immune system and human attempts to control the disease. To eliminate malaria from regions where it is deeply entrenched we need ways of monitoring what is going on in the parasite population, detecting problematic changes as soon as they arise, and executing a prompt and effective response based on a deep understanding of this natural evolutionary process. Powerful new tools to address this problem are emerging from the fast-growing field of genomic epidemiology, driven by new sequencing technologies and computational methods that allow parasite genome variation to be studied in much greater detail and in many more samples than was previously considered possible. These new tools will provide a deep understanding of what is going on in the parasite population, generating actionable knowledge for strategic planning of control interventions, for monitoring their effects and steering them for greatest impact, and for raising the alert if things start to go wrong.

  16. Malaria genomics: tracking a diverse and evolving parasite population

    PubMed Central

    Kwiatkowski, Dominic

    2015-01-01

    Malaria parasites are continually evolving to evade the immune system and human attempts to control the disease. To eliminate malaria from regions where it is deeply entrenched we need ways of monitoring what is going on in the parasite population, detecting problematic changes as soon as they arise, and executing a prompt and effective response based on a deep understanding of this natural evolutionary process. Powerful new tools to address this problem are emerging from the fast-growing field of genomic epidemiology, driven by new sequencing technologies and computational methods that allow parasite genome variation to be studied in much greater detail and in many more samples than was previously considered possible. These new tools will provide a deep understanding of what is going on in the parasite population, generating actionable knowledge for strategic planning of control interventions, for monitoring their effects and steering them for greatest impact, and for raising the alert if things start to go wrong. PMID:25733556

  17. The evolving block universe and the meshing together of times.

    PubMed

    Ellis, George F R

    2014-10-01

    It has been proposed that spacetime should be regarded as an evolving block universe, bounded to the future by the present time, which continually extends to the future. This future boundary is defined at each time by measuring proper time along Ricci eigenlines from the start of the universe. A key point, then, is that physical reality can be represented at many different scales: hence, the passage of time may be seen as different at different scales, with quantum gravity determining the evolution of spacetime itself at the Planck scale, but quantum field theory and classical physics determining the evolution of events within spacetime at larger scales. The fundamental issue then arises as to how the effective times at different scales mesh together, leading to the concepts of global and local times.

  18. Evolving management of metaplasia and dysplasia in Barrett's epithelium

    PubMed Central

    Evans, Richard P T; Mourad, Moustafa Mabrouk; Fisher, Simon G; Bramhall, Simon R

    2016-01-01

    Oesophageal cancer affects more than 450000 people worldwide and despite continued medical advancements the incidence of oesophageal cancer is increasing. Oesophageal cancer has a 5 year survival of 15%-25% and now globally attempts are made to more aggressively diagnose and treat Barrett’s oesophagus the known precursor to invasive disease. Currently diagnosis the of Barrett’s oesophagus is predominantly made after endoscopic visualisation and histopathological confirmation. Minimally invasive techniques are being developed to improve the viability of screening programs. The management of Barrett’s oesophagus can vary greatly dependent on the presence and severity of dysplasia. There is no consensus between the major international medical societies to determine and agreed surveillance and intervention pathway. In this review we analysed the current literature to demonstrate the evolving management of metaplasia and dysplasia in Barrett’s epithelium. PMID:28058012

  19. The rapidly evolving planetary nebula Hen 3-1357

    NASA Astrophysics Data System (ADS)

    Gry, C.

    Hen 3-1357 (known as the 'Stingray Nebula') is the youngest Planetary Nebula known in the sky. It has become ionized within the past few decades and its central star seems to be still rapidly evolving in the H-R diagram towards hotter effective temperatures. With this proposal we want to determine the current effective temperature of the central star and the characteristics of the stellar wind thirteen years after its discovery with IUE. This will enable us to determine whether the rapid spectral changes observed in the last few years are the consequence of an episodic post-AGB mass loss event or the result of a continuous evolution in the H-R digram. In any of these cases, the observations will help us to understand this short and, thus, still poorly known transition phase which leads to the formation of a new PN.

  20. Production and decay of evolving horizons

    NASA Astrophysics Data System (ADS)

    Nielsen, Alex B.; Visser, Matt

    2006-07-01

    We consider a simple physical model for an evolving horizon that is strongly interacting with its environment, exchanging arbitrarily large quantities of matter with its environment in the form of both infalling material and outgoing Hawking radiation. We permit fluxes of both lightlike and timelike particles to cross the horizon, and ask how the horizon grows and shrinks in response to such flows. We place a premium on providing a clear and straightforward exposition with simple formulae. To be able to handle such a highly dynamical situation in a simple manner we make one significant physical restriction—that of spherical symmetry—and two technical mathematical restrictions: (1) we choose to slice the spacetime in such a way that the spacetime foliations (and hence the horizons) are always spherically symmetric. (2) Furthermore, we adopt Painlevé Gullstrand coordinates (which are well suited to the problem because they are nonsingular at the horizon) in order to simplify the relevant calculations. Of course physics results are ultimately independent of the choice of coordinates, but this particular coordinate system yields a clean physical interpretation of the relevant physics. We find particularly simple forms for surface gravity, and for the first and second law of black hole thermodynamics, in this general evolving horizon situation. Furthermore, we relate our results to Hawking's apparent horizon, Ashtekar and co-worker's isolated and dynamical horizons, and Hayward's trapping horizon. The evolving black hole model discussed here will be of interest, both from an astrophysical viewpoint in terms of discussing growing black holes and from a purely theoretical viewpoint in discussing black hole evaporation via Hawking radiation.

  1. Risky prey behavior evolves in risky habitats

    PubMed Central

    Urban, Mark C.

    2007-01-01

    Longstanding theory in behavioral ecology predicts that prey should evolve decreased foraging rates under high predation threat. However, an alternative perspective suggests that growth into a size refuge from gape-limited predation and the future benefits of large size can outweigh the initial survival costs of intense foraging. Here, I evaluate the relative contributions of selection from a gape-limited predator (Ambystoma opacum) and spatial location to explanations of variation in foraging, growth, and survival in 10 populations of salamander larvae (Ambystoma maculatum). Salamander larvae from populations naturally exposed to intense A. opacum predation risk foraged more actively under common garden conditions. Higher foraging rates were associated with low survival in populations exposed to free-ranging A. opacum larvae. Results demonstrate that risky foraging activity can evolve in high predation-risk habitats when the dominant predators are gape-limited. This finding invites the further exploration of diverse patterns of prey foraging behavior that depends on natural variation in predator size-selectivity. In particular, prey should adopt riskier behaviors under predation threat than expected under existing risk allocation models if foraging effort directly reduces the duration of risk by growth into a size refuge. Moreover, evidence from this study suggests that foraging has evolved over microgeographic scales despite substantial modification by regional gene flow. This interaction between local selection and spatial location suggests a joint role for adaptation and maladaptation in shaping species interactions across natural landscapes, which is a finding with implications for dynamics at the population, community, and metacommunity levels. PMID:17724339

  2. Risky prey behavior evolves in risky habitats.

    PubMed

    Urban, Mark C

    2007-09-04

    Longstanding theory in behavioral ecology predicts that prey should evolve decreased foraging rates under high predation threat. However, an alternative perspective suggests that growth into a size refuge from gape-limited predation and the future benefits of large size can outweigh the initial survival costs of intense foraging. Here, I evaluate the relative contributions of selection from a gape-limited predator (Ambystoma opacum) and spatial location to explanations of variation in foraging, growth, and survival in 10 populations of salamander larvae (Ambystoma maculatum). Salamander larvae from populations naturally exposed to intense A. opacum predation risk foraged more actively under common garden conditions. Higher foraging rates were associated with low survival in populations exposed to free-ranging A. opacum larvae. Results demonstrate that risky foraging activity can evolve in high predation-risk habitats when the dominant predators are gape-limited. This finding invites the further exploration of diverse patterns of prey foraging behavior that depends on natural variation in predator size-selectivity. In particular, prey should adopt riskier behaviors under predation threat than expected under existing risk allocation models if foraging effort directly reduces the duration of risk by growth into a size refuge. Moreover, evidence from this study suggests that foraging has evolved over microgeographic scales despite substantial modification by regional gene flow. This interaction between local selection and spatial location suggests a joint role for adaptation and maladaptation in shaping species interactions across natural landscapes, which is a finding with implications for dynamics at the population, community, and metacommunity levels.

  3. Strategic Plan for the North American Breeding Bird Survey: 2006-2010

    USGS Publications Warehouse

    ,

    2007-01-01

    program to continue to meet the evolving needs of the conservation community for information on bird population change. By setting clear goals, strategies, and measures of success, this plan provides a cohesive framework and vision for maintenance and development of the BBS. The plan identifies two major goals for the BBS, with a number of strategies and objectives to achieve these goals. Over the next 5 years, progress made in addressing each long-term goal and its associated 5-year strategies and objectives will gage the plan's success. Specific actions, projected outcomes, and measures of success related to accomplishing these are outlined in Table 1, with a timeline in Table 2. The two main goals for the program, with a summary of the strategies to achieve them, are: Goal 1: Collect scientifically credible measures of the status and trends of North American bird populations at continental and regional scales. The North American Breeding Bird Survey will continue to support North American natural resource conservation through the collection of scientifically credible measures of the status and trends of continental bird populations. While doing this, the BBS will work to improve the science behind the program to better meet its mission and the changing needs of the avian conservation community. In partnership with collaborators, the BBS will address detection probability bias and habitat bias, improve analytical methods, and more fully assess and account for observer quality. Moreover, the BBS will improve the quality and breadth of avian population data through strategic increases in route density and the establishment of a Mexican BBS program. Goal 2: Ensure BBS data and analytical results are widely available and easily accessible for use by the avian conservation and management communities. At the heart of the BBS lies a four-million-record database containing more than 40 years of data on more than 600 bird species. These data are of no valu

  4. Evolvable circuit with transistor-level reconfigurability

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian (Inventor); Salazar-Lazaro, Carlos Harold (Inventor)

    2004-01-01

    An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor terminal to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.

  5. Present weather and climate: evolving conditions

    USGS Publications Warehouse

    Hoerling, Martin P; Dettinger, Michael; Wolter, Klaus; Lukas, Jeff; Eischeid, Jon K.; Nemani, Rama; Liebmann, Brant; Kunkel, Kenneth E.

    2013-01-01

    This chapter assesses weather and climate variability and trends in the Southwest, using observed climate and paleoclimate records. It analyzes the last 100 years of climate variability in comparison to the last 1,000 years, and links the important features of evolving climate conditions to river flow variability in four of the region’s major drainage basins. The chapter closes with an assessment of the monitoring and scientific research needed to increase confidence in understanding when climate episodes, events, and phenomena are attributable to human-caused climate change.

  6. Cobalt-phosphate oxygen-evolving compound.

    PubMed

    Kanan, Matthew W; Surendranath, Yogesh; Nocera, Daniel G

    2009-01-01

    The utilization of solar energy on a large scale requires efficient storage. Solar-to-fuels has the capacity to meet large scale storage needs as demonstrated by natural photosynthesis. This process uses sunlight to rearrange the bonds of water to furnish O2 and an H2-equivalent. We present a tutorial review of our efforts to develop an amorphous cobalt-phosphate catalyst that oxidizes water to O2. The use of earth-abundant materials, operation in water at neutral pH, and the formation of the catalyst in situ captures functional elements of the oxygen evolving complex of Photosystem II.

  7. An evolving paradigm for the secretory pathway?

    PubMed Central

    Lippincott-Schwartz, Jennifer

    2011-01-01

    The paradigm that the secretory pathway consists of a stable endoplasmic reticulum and Golgi apparatus, using discrete transport vesicles to exchange their contents, gained important support from groundbreaking biochemical and genetic studies during the 1980s. However, the subsequent development of new imaging technologies with green fluorescent protein introduced data on dynamic processes not fully accounted for by the paradigm. As a result, we may be seeing an example of how a paradigm is evolving to account for the results of new technologies and their new ways of describing cellular processes. PMID:22039065

  8. SALT Spectroscopy of Evolved Massive Stars

    NASA Astrophysics Data System (ADS)

    Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.

    2017-06-01

    Long-slit spectroscopy with the Southern African Large Telescope (SALT) of central stars of mid-infrared nebulae detected with the Spitzer Space Telescope and Wide-Field Infrared Survey Explorer (WISE) led to the discovery of numerous candidate luminous blue variables (cLBVs) and other rare evolved massive stars. With the recent advent of the SALT fiber-fed high-resolution echelle spectrograph (HRS), a new perspective for the study of these interesting objects is appeared. Using the HRS we obtained spectra of a dozen newly identified massive stars. Some results on the recently identified cLBV Hen 3-729 are presented.

  9. Investigating Evolved Compositions Around Wolf Crater

    NASA Technical Reports Server (NTRS)

    Greenhagen, B. T.; Cahill, J. T. S.; Jolliff, B. L.; Lawrence, S. J.; Glotch, T. D.

    2017-01-01

    Wolf crater is an irregularly shaped, approximately 25 km crater in the south-central portion of Mare Nubium on the lunar nearside. While not previously identified as a lunar "red spot", Wolf crater was identified as a Th anomaly by Lawrence and coworkers. We have used data from the Lunar Reconnaissance Orbiter (LRO) to determine the area surrounding Wolf crater has composition more similar to highly evolved, non-mare volcanic structures than typical lunar crustal lithology. In this presentation, we will investigate the geomorphology and composition of the Wolf crater and discuss implications for the origin of the anomalous terrain.

  10. Scar State on Time-evolving Wavepacket

    NASA Astrophysics Data System (ADS)

    Tomiya, Mitsuyoshi; Tsuyuki, Hiroyoshi; Kawamura, Kentaro; Sakamoto, Shoichi; Heller, Eric J.

    2015-09-01

    The scar-like enhancement is found in the accumulation of the time-evolving wavepacket in stadium billiard. It appears close to unstable periodic orbits, when the wavepackets are launched along the orbits. The enhancement is essentially due to the same mechanism of the well-known scar states in stationary eigenstates. The weighted spectral function reveals that the enhancement is the pileup of contributions from scar states on the same periodic orbit. The availavility of the weighted spectrum to the semiclassical approximation is also disscussed.

  11. f( R) gravity solutions for evolving wormholes

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Subhra; Chakraborty, Subenoy

    2017-08-01

    The scalar-tensor f( R) theory of gravity is considered in the framework of a simple inhomogeneous space-time model. In this research we use the reconstruction technique to look for possible evolving wormhole solutions within viable f( R) gravity formalism. These f( R) models are then constrained so that they are consistent with existing experimental data. Energy conditions related to the matter threading the wormhole are analyzed graphically and are in general found to obey the null energy conditions (NEC) in regions around the throat, while in the limit f(R)=R, NEC can be violated at large in regions around the throat.

  12. Genetic trends and breed overlap derived from multiple-breed genetic evaluations of beef cattle for growth traits.

    PubMed

    Sullivan, P G; Wilton, J W; Miller, S P; Banks, L R

    1999-08-01

    Genetic evaluations for a multiple-breed population of beef cattle were used to estimate genetic trends for five breeds, and genetic differences and overlap among 14 breeds. Genetic evaluations studied were for direct contributions to birth weight, gain from birth to 200 and 365 d, and maternal contribution to gain from birth to 200 d. Almost all genetic trends were positive, but the magnitude of the trends varied among breeds. Trends were nonlinear between 1985 and 1995 for most breed and trait combinations. The rates of increase in genetic trends were generally higher for the lighter weight breeds, and lighter weight breeds had faster growth rate genetic trends at 1995 than the heavier breeds. Genetic trend estimates for yearling gain at 1995 were 2.46, 2.23, 1.73, 1.70, and 1.46 kg/yr for Angus, Hereford, Limousin, Charolais, and Simmental, respectively. Corresponding birth weight genetic trends were .130, .226, .049, .130, and .048 kg/yr. Mean genetic differences between breeds have been decreasing in magnitude due to these differences in genetic trends between heavier and lighter breeds. Genetic variation for the traits studied seemed to be greater within than between breeds for calves born and cows calving between 1993 and 1995. Genetic trends at 1995 suggest that ratios of within:between breed variation will increase and that across-breed genetic improvement initiatives for growth traits will become more important in the future.

  13. Genetic diversity analyses reveal first insights into breed-specific selection signatures within Swiss goat breeds.

    PubMed

    Burren, A; Neuditschko, M; Signer-Hasler, H; Frischknecht, M; Reber, I; Menzi, F; Drögemüller, C; Flury, C

    2016-12-01

    We used genotype data from the caprine 50k Illumina BeadChip for the assessment of genetic diversity within and between 10 local Swiss goat breeds. Three different cluster methods allowed the goat samples to be assigned to the respective breed groups, whilst the samples of Nera Verzasca and Tessin Grey goats could not be differentiated from each other. The results of the different genetic diversity measures show that Appenzell, Toggenburg, Valais and Booted goats should be prioritized in future conservation activities. Furthermore, we examined runs of homozygosity (ROH) and compared genomic inbreeding coefficients based on ROH (FROH ) with pedigree-based inbreeding coefficients (FPED ). The linear relationship between FROH and FPED was confirmed for goats by including samples from the three main breeds (Saanen, Chamois and Toggenburg goats). FROH appears to be a suitable measure for describing levels of inbreeding in goat breeds with missing pedigree information. Finally, we derived selection signatures between the breeds. We report a total of 384 putative selection signals. The 25 most significant windows contained genes known for traits such as: coat color variation (MITF, KIT, ASIP), growth (IGF2, IGF2R, HRAS, FGFR3) and milk composition (PITX2). Several other putative genes involved in the formation of populations, which might have been selected for adaptation to the alpine environment, are highlighted. The results provide a contemporary background for the management of genetic diversity in local Swiss goat breeds. © 2016 Stichting International Foundation for Animal Genetics.

  14. Variation in the prion protein sequence in Dutch goat breeds.

    PubMed

    Windig, J J; Hoving, R A H; Priem, J; Bossers, A; van Keulen, L J M; Langeveld, J P M

    2016-10-01

    Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined for six goat breeds in the Netherlands. Overall frequencies in Dutch goats were determined from 768 brain tissue samples in 2005, 766 in 2008 and 300 in 2012, derived from random sampling for the national scrapie surveillance without knowledge of the breed. Breed specific frequencies were determined in the winter 2013/2014 by sampling 300 breeding animals from the main breeders of the different breeds. Detailed analysis of the scrapie-resistant K222 haplotype was carried out in 2014 for 220 Dutch Toggenburger goats and in 2015 for 942 goats from the Saanen derived White Goat breed. Nine haplotypes were identified in the Dutch breeds. Frequencies for non-wild type haplotypes were generally low. Exception was the K222 haplotype in the Dutch Toggenburger (29%) and the S146 haplotype in the Nubian and Boer breeds (respectively 7 and 31%). The frequency of the K222 haplotype in the Toggenburger was higher than for any other breed reported in literature, while for the White Goat breed it was with 3.1% similar to frequencies of other Saanen or Saanen derived breeds. Further evidence was found for the existence of two M142 haplotypes, M142 /S240 and M142 /P240 . Breeds vary in haplotype frequencies but frequencies of resistant genotypes are generally low and consequently selective breeding for scrapie resistance can only be slow but will benefit from animals identified in this study. The unexpectedly high frequency of the K222 haplotype in the Dutch Toggenburger underlines the need for conservation of rare breeds in order to conserve genetic diversity rare or absent in other breeds. © 2016 Blackwell Verlag GmbH.

  15. Maximizing colonial waterbirds' breeding events using identified ecological thresholds and environmental flow management.

    PubMed

    Bino, Gilad; Steinfeld, Celine; Kingsford, Richard T

    2014-01-01

    Global wetland biodiversity loss continues unabated, driven by increased demand for freshwater. A key strategy for conservation management of freshwater systems is to maintain the quantity and quality of the natural water regimes, including the frequency and timing of flows. Formalizing an ecological model depicting the key ecological components and the underlying processes of cause and effect is required for successful conservation management. Models linking hydrology with ecological responses can prove to be an invaluable tool for robust decision-making of environmental flows. Here, we explored alternative water management strategies and identified maximal strategies for successful long-term management of colonial waterbirds in the Macquarie Marshes, Australia. We modeled fluctuations in breeding abundances of 10 colonial waterbird species over the past quarter century (1986-2010). Clear relationships existed between flows and breeding, both in frequencies and total abundances, with a strong linear relationship for flows > 200 GL. Thresholds emerged for triggering breeding events in all 10 species, but these varied among species. Three species displayed a sharp threshold response between 100 GL and 250 GL. These had a breeding probability of 0.5 when flows were > 180 GL and a 0.9 probability of breeding with flows > 350 GL. The remaining species had a probability greater than 0.5 of breeding with flows > 400 GL. Using developed models, we examined the effects of five environmental flow management strategies on the variability of flows and subsequent likelihood of breeding. Management to different target volumes of environmental flows affected overall and specific breeding probabilities. The likelihood of breeding for all 10 colonial waterbirds increased from a regulated historical mean (+/-SD) of 0.36 +/- 0.09 to 0.53 +/- 0.14, an improvement of 47.5% +/- 18.7%. Management of complex ecosystems depends on good understanding of the responses of organisms to the

  16. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Approval of cooperative breeding programs... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the...

  17. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 1 2014-10-01 2014-10-01 false Approval of cooperative breeding programs... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the...

  18. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Approval of cooperative breeding programs... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the...

  19. Breeding design considerations for coastal Douglas-fir.

    Treesearch

    Randy. Johnson

    1998-01-01

    The basic principles of designing forest tree breeding programs are reviewed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Pacific Northwest. Breeding populations are discussed given current and future breeding zone sizes and seed orchard designs. Seed orchard composition is discussed for potential genetic gain and maintaining...

  20. Genomic predictions for crossbreds from all-breed data

    USDA-ARS?s Scientific Manuscript database

    Genomic predictions of transmitting ability (GPTAs) for crossbred animals were computed from marker effects of 5 dairy breeds weighted by each breed’s genomic contribution to the crossbreds. Estimates of genomic breed composition are labeled breed base representation (BBR) and are reported since May...

  1. Pedigree analysis of eight Spanish beef cattle breeds

    PubMed Central

    Gutiérrez, Juan Pablo; Altarriba, Juan; Díaz, Clara; Quintanilla, Raquel; Cañón, Javier; Piedrafita, Jesús

    2003-01-01

    The genetic structure of eight Spanish autochthonous populations (breeds) of beef cattle were studied from pedigree records. The populations studied were: Alistana and Sayaguesa (minority breeds), Avileña – Negra Ibérica and Morucha ("dehesa" breeds, with a scarce incidence of artificial insemination), and mountain breeds, including Asturiana de los Valles, Asturiana de la Montaña and Pirenaica, with extensive use of AI. The Bruna dels Pirineus breed possesses characteristics which make its classification into one of the former groups difficult. There was a large variation between breeds both in the census and the number of herds. Generation intervals ranged from 3.7 to 5.5 years, tending to be longer as the population size was larger. The effective numbers of herds suggest that a small number of herds behaves as a selection nucleus for the rest of the breed. The complete generation equivalent has also been greatly variable, although in general scarce, with the exception of the Pirenaica breed, with a mean of 3.8. Inbreeding effective population sizes were actually small (21 to 127), especially in the mountain-type breeds. However, the average relatedness computed for these breeds suggests that a slight exchange of animals between herds will lead to a much more favourable evolution of inbreeding. The effective number of founders and ancestors were also variable among breeds, although in general the breeds behaved as if they were founded by a small number of animals (25 to 163). PMID:12605850

  2. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the Director... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Approval of cooperative breeding programs...

  3. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the Director... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Approval of cooperative breeding programs...

  4. The emotion system promotes diversity and evolvability

    PubMed Central

    Giske, Jarl; Eliassen, Sigrunn; Fiksen, Øyvind; Jakobsen, Per J.; Aksnes, Dag L.; Mangel, Marc; Jørgensen, Christian

    2014-01-01

    Studies on the relationship between the optimal phenotype and its environment have had limited focus on genotype-to-phenotype pathways and their evolutionary consequences. Here, we study how multi-layered trait architecture and its associated constraints prescribe diversity. Using an idealized model of the emotion system in fish, we find that trait architecture yields genetic and phenotypic diversity even in absence of frequency-dependent selection or environmental variation. That is, for a given environment, phenotype frequency distributions are predictable while gene pools are not. The conservation of phenotypic traits among these genetically different populations is due to the multi-layered trait architecture, in which one adaptation at a higher architectural level can be achieved by several different adaptations at a lower level. Our results emphasize the role of convergent evolution and the organismal level of selection. While trait architecture makes individuals more constrained than what has been assumed in optimization theory, the resulting populations are genetically more diverse and adaptable. The emotion system in animals may thus have evolved by natural selection because it simultaneously enhances three important functions, the behavioural robustness of individuals, the evolvability of gene pools and the rate of evolutionary innovation at several architectural levels. PMID:25100697

  5. Early formation of evolved asteroidal crust.

    PubMed

    Day, James M D; Ash, Richard D; Liu, Yang; Bellucci, Jeremy J; Rumble, Douglas; McDonough, William F; Walker, Richard J; Taylor, Lawrence A

    2009-01-08

    Mechanisms for the formation of crust on planetary bodies remain poorly understood. It is generally accepted that Earth's andesitic continental crust is the product of plate tectonics, whereas the Moon acquired its feldspar-rich crust by way of plagioclase flotation in a magma ocean. Basaltic meteorites provide evidence that, like the terrestrial planets, some asteroids generated crust and underwent large-scale differentiation processes. Until now, however, no evolved felsic asteroidal crust has been sampled or observed. Here we report age and compositional data for the newly discovered, paired and differentiated meteorites Graves Nunatak (GRA) 06128 and GRA 06129. These meteorites are feldspar-rich, with andesite bulk compositions. Their age of 4.52 +/- 0.06 Gyr demonstrates formation early in Solar System history. The isotopic and elemental compositions, degree of metamorphic re-equilibration and sulphide-rich nature of the meteorites are most consistent with an origin as partial melts from a volatile-rich, oxidized asteroid. GRA 06128 and 06129 are the result of a newly recognized style of evolved crust formation, bearing witness to incomplete differentiation of their parent asteroid and to previously unrecognized diversity of early-formed materials in the Solar System.

  6. Evolvability of an Optimal Recombination Rate

    PubMed Central

    Lobkovsky, Alexander E.; Wolf, Yuri I.; Koonin, Eugene V.

    2016-01-01

    Evolution and maintenance of genetic recombination and its relation to the mutational process is a long-standing, fundamental problem in evolutionary biology that is linked to the general problem of evolution of evolvability. We explored a stochastic model of the evolution of recombination using additive fitness and infinite allele assumptions but no assumptions on the sign or magnitude of the epistasis and the distribution of mutation effects. In this model, fluctuating negative epistasis and predominantly deleterious mutations arise naturally as a consequence of the additive fitness and a reservoir from which new alleles arrive with a fixed distribution of fitness effects. Analysis of the model revealed a nonmonotonic effect of recombination intensity on fitness, with an optimal recombination rate value which maximized fitness in steady state. The optimal recombination rate depended on the mutation rate and was evolvable, that is, subject to selection. The predictions of the model were compatible with the observations on the dependence between genome rearrangement rate and gene flux in microbial genomes. PMID:26660159

  7. BOOK REVIEW: OPENING SCIENCE, THE EVOLVING GUIDE ...

    EPA Pesticide Factsheets

    The way we get our funding, collaborate, do our research, and get the word out has evolved over hundreds of years but we can imagine a more open science world, largely facilitated by the internet. The movement towards this more open way of doing and presenting science is coming, and it is not taking hundreds of years. If you are interested in these trends, and would like to find out more about where this is all headed and what it means to you, consider downloding Opening Science, edited by Sönke Bartling and Sascha Friesike, subtitled The Evolving Guide on How the Internet is Changing Research, Collaboration, and Scholarly Publishing. In 26 chapters by various authors from a range of disciplines the book explores the developing world of open science, starting from the first scientific revolution and bringing us to the next scientific revolution, sometimes referred to as “Science 2.0”. Some of the articles deal with the impact of the changing landscape of how science is done, looking at the impact of open science on Academia, or journal publishing, or medical research. Many of the articles look at the uses, pitfalls, and impact of specific tools, like microblogging (think Twitter), social networking, and reference management. There is lots of discussion and definition of terms you might use or misuse like “altmetrics” and “impact factor”. Science will probably never be completely open, and Twitter will probably never replace the journal article,

  8. Evolving Dark Energy with w =/ -1

    SciTech Connect

    Hall, Lawrence J.; Nomura, Yasunori; Oliver, Steven J.

    2005-03-31

    Theories of evolving quintessence are constructed that generically lead to deviations from the w = -1 prediction of non-evolving dark energy. The small mass scale that governs evolution, m_\\phi \\approx 10^-33 eV, is radiatively stable, and the"Why Now?'' problem is solved. These results rest crucially on seesaw cosmology: in broad outline, fundamental physics and cosmology can be understood from only two mass scales, the weak scale, v, and the Planck scale, M. Requiring a scale of dark energy \\rho_DE^1/4 governed by v^2/M, and a radiatively stable evolution rate m_\\phi given by v^4/M^3, leads to a distinctive form for the equation of state w(z) that follows from a cosine quintessence potential. An explicit hidden axion model is constructed. Dark energy resides in the potential of the axion field which is generated by a new QCD-like force that gets strong at the scale \\Lambda \\approx v^2/M \\approx \\rho_DE^1/4. The evolution rate is given by a second seesaw that leads to the axion mass, m_\\phi \\approx \\Lambda^2/f, with f \\approx M.

  9. Novel cooperation experimentally evolved between species.

    PubMed

    Harcombe, William

    2010-07-01

    Cooperation violates the view of "nature red in tooth and claw" that prevails in our understanding of evolution, yet examples of cooperation abound. Most work has focused on maintenance of cooperation within a single species through mechanisms such as kin selection. The factors necessary for the evolutionary origin of aiding unrelated individuals such as members of another species have not been experimentally tested. Here, I demonstrate that cooperation between species can be evolved in the laboratory if (1) there is preexisting reciprocation or feedback for cooperation, and (2) reciprocation is preferentially received by cooperative genotypes. I used a two species system involving Salmonella enterica ser. Typhimurium and an Escherichia coli mutant unable to synthesize an essential amino acid. In lactose media Salmonella consumes metabolic waste from E. coli, thus creating a mechanism of reciprocation for cooperation. Growth in a spatially structured environment assured that the benefits of cooperation were preferentially received by cooperative genotypes. Salmonella evolved to aid E. coli by excreting a costly amino acid, however this novel cooperation disappeared if the waste consumption or spatial structure were removed. This study builds on previous work to demonstrate an experimental origin of interspecific cooperation, and to test the factors necessary for such interactions to arise.

  10. Shaping the outflows of evolved stars

    NASA Astrophysics Data System (ADS)

    Mohamed, Shazrene

    2015-08-01

    Both hot and cool evolved stars, e.g., red (super)giants and Wolf-Rayet stars, lose copious amounts of mass, momentum and mechanical energy through powerful, dense stellar winds. The interaction of these outflows with their surroundings results in highly structured and complex circumstellar environments, often featuring knots, arcs, shells and spirals. Recent improvements in computational power and techniques have led to the development of detailed, multi-dimensional simulations that have given new insight into the origin of these structures, and better understanding of the physical mechanisms driving their formation. In this talk, I will discuss three of the main mechanisms that shape the outflows of evolved stars:- interaction with the interstellar medium (ISM), i.e., wind-ISM interactions- interaction with a stellar wind, either from a previous phase of evolution or the wind from a companion star, i.e., wind-wind interactions- and interaction with a companion star that has a weak or insignicant outflow (e.g., a compact companion such as a neutron star or black hole), i.e., wind-companion interactions.I will also highlight the broader implications and impact of these stellar wind interactions for other phenomena, e.g, for symbiotic and X-ray binaries, supernovae and Gamma-ray bursts.

  11. Hierarchical decomposition of dynamically evolving regulatory networks.

    PubMed

    Ay, Ahmet; Gong, Dihong; Kahveci, Tamer

    2015-05-15

    Gene regulatory networks describe the interplay between genes and their products. These networks control almost every biological activity in the cell through interactions. The hierarchy of genes in these networks as defined by their interactions gives important insights into how these functions are governed. Accurately determining the hierarchy of genes is however a computationally difficult problem. This problem is further complicated by the fact that an intrinsic characteristic of regulatory networks is that the wiring of interactions can change over time. Determining how the hierarchy in the gene regulatory networks changes with dynamically evolving network topology remains to be an unsolved challenge. In this study, we develop a new method, named D-HIDEN (Dynamic-HIerarchical DEcomposition of Networks) to find the hierarchy of the genes in dynamically evolving gene regulatory network topologies. Unlike earlier methods, which recompute the hierarchy from scratch when the network topology changes, our method adapts the hierarchy based on the wiring of the interactions only for the nodes which have the potential to move in the hierarchy. We compare D-HIDEN to five currently available hierarchical decomposition methods on synthetic and real gene regulatory networks. Our experiments demonstrate that D-HIDEN significantly outperforms existing methods in running time, accuracy, or both. Furthermore, our method is robust against dynamic changes in hierarchy. Our experiments on human gene regulatory networks suggest that our method may be used to reconstruct hierarchy in gene regulatory networks.

  12. Evolving MEMS Resonator Designs for Fabrication

    NASA Technical Reports Server (NTRS)

    Hornby, Gregory S.; Kraus, William F.; Lohn, Jason D.

    2008-01-01

    Because of their small size and high reliability, microelectromechanical (MEMS) devices have the potential to revolution many areas of engineering. As with conventionally-sized engineering design, there is likely to be a demand for the automated design of MEMS devices. This paper describes our current status as we progress toward our ultimate goal of using an evolutionary algorithm and a generative representation to produce designs of a MEMS device and successfully demonstrate its transfer to an actual chip. To produce designs that are likely to transfer to reality, we present two ways to modify evaluation of designs. The first is to add location noise, differences between the actual dimensions of the design and the design blueprint, which is a technique we have used for our work in evolving antennas and robots. The second method is to add prestress to model the warping that occurs during the extreme heat of fabrication. In future we expect to fabricate and test some MEMS resonators that are evolved in this way.

  13. Have plants evolved to self-immolate?

    PubMed Central

    Bowman, David M. J. S.; French, Ben J.; Prior, Lynda D.

    2014-01-01

    By definition fire prone ecosystems have highly combustible plants, leading to the hypothesis, first formally stated by Mutch in 1970, that community flammability is the product of natural selection of flammable traits. However, proving the “Mutch hypothesis” has presented an enormous challenge for fire ecologists given the difficulty in establishing cause and effect between landscape fire and flammable plant traits. Individual plant traits (such as leaf moisture content, retention of dead branches and foliage, oil rich foliage) are known to affect the flammability of plants but there is no evidence these characters evolved specifically to self-immolate, although some of these traits may have been secondarily modified to increase the propensity to burn. Demonstrating individual benefits from self-immolation is extraordinarily difficult, given the intersection of the physical environmental factors that control landscape fire (fuel production, dryness and ignitions) with community flammability properties that emerge from numerous traits of multiple species (canopy cover and litter bed bulk density). It is more parsimonious to conclude plants have evolved mechanisms to tolerate, but not promote, landscape fire. PMID:25414710

  14. BOOK REVIEW: OPENING SCIENCE, THE EVOLVING GUIDE ...

    EPA Pesticide Factsheets

    The way we get our funding, collaborate, do our research, and get the word out has evolved over hundreds of years but we can imagine a more open science world, largely facilitated by the internet. The movement towards this more open way of doing and presenting science is coming, and it is not taking hundreds of years. If you are interested in these trends, and would like to find out more about where this is all headed and what it means to you, consider downloding Opening Science, edited by Sönke Bartling and Sascha Friesike, subtitled The Evolving Guide on How the Internet is Changing Research, Collaboration, and Scholarly Publishing. In 26 chapters by various authors from a range of disciplines the book explores the developing world of open science, starting from the first scientific revolution and bringing us to the next scientific revolution, sometimes referred to as “Science 2.0”. Some of the articles deal with the impact of the changing landscape of how science is done, looking at the impact of open science on Academia, or journal publishing, or medical research. Many of the articles look at the uses, pitfalls, and impact of specific tools, like microblogging (think Twitter), social networking, and reference management. There is lots of discussion and definition of terms you might use or misuse like “altmetrics” and “impact factor”. Science will probably never be completely open, and Twitter will probably never replace the journal article,

  15. The Comet Cometh: Evolving Developmental Systems.

    PubMed

    Jaeger, Johannes; Laubichler, Manfred; Callebaut, Werner

    In a recent opinion piece, Denis Duboule has claimed that the increasing shift towards systems biology is driving evolutionary and developmental biology apart, and that a true reunification of these two disciplines within the framework of evolutionary developmental biology (EvoDevo) may easily take another 100 years. He identifies methodological, epistemological, and social differences as causes for this supposed separation. Our article provides a contrasting view. We argue that Duboule's prediction is based on a one-sided understanding of systems biology as a science that is only interested in functional, not evolutionary, aspects of biological processes. Instead, we propose a research program for an evolutionary systems biology, which is based on local exploration of the configuration space in evolving developmental systems. We call this approach-which is based on reverse engineering, simulation, and mathematical analysis-the natural history of configuration space. We discuss a number of illustrative examples that demonstrate the past success of local exploration, as opposed to global mapping, in different biological contexts. We argue that this pragmatic mode of inquiry can be extended and applied to the mathematical analysis of the developmental repertoire and evolutionary potential of evolving developmental mechanisms and that evolutionary systems biology so conceived provides a pragmatic epistemological framework for the EvoDevo synthesis.

  16. Evolvability of an Optimal Recombination Rate.

    PubMed

    Lobkovsky, Alexander E; Wolf, Yuri I; Koonin, Eugene V

    2015-12-10

    Evolution and maintenance of genetic recombination and its relation to the mutational process is a long-standing, fundamental problem in evolutionary biology that is linked to the general problem of evolution of evolvability. We explored a stochastic model of the evolution of recombination using additive fitness and infinite allele assumptions but no assumptions on the sign or magnitude of the epistasis and the distribution of mutation effects. In this model, fluctuating negative epistasis and predominantly deleterious mutations arise naturally as a consequence of the additive fitness and a reservoir from which new alleles arrive with a fixed distribution of fitness effects. Analysis of the model revealed a nonmonotonic effect of recombination intensity on fitness, with an optimal recombination rate value which maximized fitness in steady state. The optimal recombination rate depended on the mutation rate and was evolvable, that is, subject to selection. The predictions of the model were compatible with the observations on the dependence between genome rearrangement rate and gene flux in microbial genomes.

  17. Caterpillars evolved from onychophorans by hybridogenesis.

    PubMed

    Williamson, Donald I

    2009-11-24

    I reject the Darwinian assumption that larvae and their adults evolved from a single common ancestor. Rather I posit that, in animals that metamorphose, the basic types of larvae originated as adults of different lineages, i.e., larvae were transferred when, through hybridization, their genomes were acquired by distantly related animals. "Caterpillars," the name for eruciforms with thoracic and abdominal legs, are larvae of lepidopterans, hymenopterans, and mecopterans (scorpionflies). Grubs and maggots, including the larvae of beetles, bees, and flies, evolved from caterpillars by loss of legs. Caterpillar larval organs are dismantled and reconstructed in the pupal phase. Such indirect developmental patterns (metamorphoses) did not originate solely by accumulation of random mutations followed by natural selection; rather they are fully consistent with my concept of evolution by hybridogenesis. Members of the phylum Onychophora (velvet worms) are proposed as the evolutionary source of caterpillars and their grub or maggot descendants. I present a molecular biological research proposal to test my thesis. By my hypothesis 2 recognizable sets of genes are detectable in the genomes of all insects with caterpillar grub- or maggot-like larvae: (i) onychophoran genes that code for proteins determining larval morphology/physiology and (ii) sequentially expressed insect genes that code for adult proteins. The genomes of insects and other animals that, by contrast, entirely lack larvae comprise recognizable sets of genes from single animal common ancestors.

  18. Collapse of cooperation in evolving games

    PubMed Central

    Stewart, Alexander J.; Plotkin, Joshua B.

    2014-01-01

    Game theory provides a quantitative framework for analyzing the behavior of rational agents. The Iterated Prisoner’s Dilemma in particular has become a standard model for studying cooperation and cheating, with cooperation often emerging as a robust outcome in evolving populations. Here we extend evolutionary game theory by allowing players’ payoffs as well as their strategies to evolve in response to selection on heritable mutations. In nature, many organisms engage in mutually beneficial interactions and individuals may seek to change the ratio of risk to reward for cooperation by altering the resources they commit to cooperative interactions. To study this, we construct a general framework for the coevolution of strategies and payoffs in arbitrary iterated games. We show that, when there is a tradeoff between the benefits and costs of cooperation, coevolution often leads to a dramatic loss of cooperation in the Iterated Prisoner’s Dilemma. The collapse of cooperation is so extreme that the average payoff in a population can decline even as the potential reward for mutual cooperation increases. Depending upon the form of tradeoffs, evolution may even move away from the Iterated Prisoner’s Dilemma game altogether. Our work offers a new perspective on the Prisoner’s Dilemma and its predictions for cooperation in natural populations; and it provides a general framework to understand the coevolution of strategies and payoffs in iterated interactions. PMID:25422421

  19. Collapse of cooperation in evolving games.

    PubMed

    Stewart, Alexander J; Plotkin, Joshua B

    2014-12-09

    Game theory provides a quantitative framework for analyzing the behavior of rational agents. The Iterated Prisoner's Dilemma in particular has become a standard model for studying cooperation and cheating, with cooperation often emerging as a robust outcome in evolving populations. Here we extend evolutionary game theory by allowing players' payoffs as well as their strategies to evolve in response to selection on heritable mutations. In nature, many organisms engage in mutually beneficial interactions and individuals may seek to change the ratio of risk to reward for cooperation by altering the resources they commit to cooperative interactions. To study this, we construct a general framework for the coevolution of strategies and payoffs in arbitrary iterated games. We show that, when there is a tradeoff between the benefits and costs of cooperation, coevolution often leads to a dramatic loss of cooperation in the Iterated Prisoner's Dilemma. The collapse of cooperation is so extreme that the average payoff in a population can decline even as the potential reward for mutual cooperation increases. Depending upon the form of tradeoffs, evolution may even move away from the Iterated Prisoner's Dilemma game altogether. Our work offers a new perspective on the Prisoner's Dilemma and its predictions for cooperation in natural populations; and it provides a general framework to understand the coevolution of strategies and payoffs in iterated interactions.

  20. Haploids: Constraints and opportunities in plant breeding.

    PubMed

    Dwivedi, Sangam L; Britt, Anne B; Tripathi, Leena; Sharma, Shivali; Upadhyaya, Hari D; Ortiz, Rodomiro

    2015-11-01

    The discovery of haploids in higher plants led to the use of doubled haploid (DH) technology in plant breeding. This article provides the state of the art on DH technology including the induction and identification of haploids, what factors influence haploid induction, molecular basis of microspore embryogenesis, the genetics underpinnings of haploid induction and its use in plant breeding, particularly to fix traits and unlock genetic variation. Both in vitro and in vivo methods have been used to induce haploids that are thereafter chromosome doubled to produce DH. Various heritable factors contribute to the successful induction of haploids, whose genetics is that of a quantitative trait. Genomic regions associated with in vitro and in vivo DH production were noted in various crops with the aid of DNA markers. It seems that F2 plants are the most suitable for the induction of DH lines than F1 plants. Identifying putative haploids is a key issue in haploid breeding. DH technology in Brassicas and cereals, such as barley, maize, rice, rye and wheat, has been improved and used routinely in cultivar development, while in other food staples such as pulses and root crops the technology has not reached to the stage leading to its application in plant breeding. The centromere-mediated haploid induction system has been used in Arabidopsis, but not yet in crops. Most food staples are derived from genomic resources-rich crops, including those with sequenced reference genomes. The integration of genomic resources with DH technology provides new opportunities for the improving selection methods, maximizing selection gains and accelerate cultivar development. Marker-aided breeding and DH technology have been used to improve host plant resistance in barley, rice, and wheat. Multinational seed companies are using DH technology in large-scale production of inbred lines for further development of hybrid cultivars, particularly in maize. The public sector provides support to